Watching Scott Guthrie's keynote at Mix07 right now. The word is finally out - and wow. Silverlight is not just a Flash alternative - it is a cross platform, cross browser .NET runtime and framework. C#, VB, any .NET language driving display in the browser, running on the client side, on other platforms.

Beta for 1.0 is out today, available on www.silverlight.net.

You can even debug cross platform with the .NET code running in a Mac browser. I think we are not far from stepping through the time space continuum now...

Its been a sparse year of blogging due to a lot of overlapping commitments, but I am going to try to remedy that now that I am digging my way out.

A couple of great articles on VSTS and team development have recently been posted on CodePlex. The first is some general guidance for structuring your projects in team system:

http://www.codeplex.com/BranchingGuidance/Wiki/View.aspx?title=Guidance%20for%20Structuring%20Team%20Projects

The other is guidance on branching and merging:

http://www.codeplex.com/BranchingGuidance/

Some good reading on using TFS right for your team.

For those of you looking for the ClickOnce Community Resource Kit I wrote for the Patterns and Practices Smart Client Software Factory team, you may have found that it has disappeared from its old location on GotDotNet.

In case you haven't heard, GotDotNet is slowly fading away (known as dying a slow death in some circles) and CodePlex has replaced it as the place that Microsoft will put community resources.  So if you go looking for something on GotDotNet and don't find it, make sure you do a search on CodePlex.

The download for my ClickOnce Community Resource Kit can be found here:

http://www.codeplex.com/smartclient/Project/FileDownload.aspx?DownloadId=5060

on the Wiki for the Smart Client Guidance.

I recorded a dnrTV with Carl a while back on WPF and it was posted last week. I'll be recording a part 2 this week so keep your eyes out for that. This episode gives a good overview of what programming WPF is like (for now until the tools evolve some more) and what the structure of a WPF application is. Part 2 will dive deeper into data binding, styles and resources, as well as a few other things.

Here are the slides and demos from last week's webcast. Keep in mind that you will need to add a Modified DateTime column and respective stored procedures to your database to be able to run the code as it was demo'ed in the webcast. The demo code includes my CodeSmith templates for generating those stored procedures and also one for making the coumn modification scripts for you if you want to do it to all the tables in your database that are transactional. There is also a SQL script just for doing the Employees table in Northwind, which was all I used in the demos.

Slides

Demos

I've had several people ask questions surrounding how to get a pfx file to use for ClickOnce manifest signing when you have purchased a real certificate from a provider like Verisign or Comodo (www.instantssl.com - a great, cheaper alternative that has its root issuer already installed as a trusted root certification authority).

Usually when you purchase a certificate, the process involves going to the provider's site, such as instantssl.com, providing your contact information online and entering payment information. The certificate issuer must then verify your identity through some means (corporate DUNS number, business license, bank statement, utility bill, etc.). Once they have done that, they will allow you to download and install your certificate through your browser. They should also provide you with a separate download or generation of a .pvk (private key) file that will contain the private key portion of your certificate. They may or may not provide you a download of a .spc or .cer file that just contains the public key portion of your certificate. If they do not provide a download of the .spc file, you may have to export it from your certificate store after the browser installs it as described later in this post.

Step 1: Download and install pvkimprt.exe
If you have a .spc or .cer file and a .pvk file, then you have the pieces you need to create a .pfx file. You will need to download,expand, and install the pfximprt tool,  which you can get here:

http://www.microsoft.com/downloads/details.aspx?FamilyID=F9992C94-B129-46BC-B240-414BDFF679A7&displaylang=EN

Generate an install a public/private key pair certificate in your store
To generate a pfx file from an spc/cer and pvk file, do the following:
1. Open a command prompt and run pvkimprt, passing the spc and pvk file:
C:\>"C:\Program Files\Pvkimprt\pvkimprt.exe" softinsight_comodo.spc softinsight_comodo.pvk
2. You will be prompted for a password for the pvk file as shown in Figure 1. The password is the one you provided when you ordered the certificate or when the pvk file was issued to you.

Figure 1

3. After entering your password and clicking OK, the certificate import wizard will launch as shown in Figure 2.

Figure 2

4. Click Next, and you will be prompted as shown in Figure 3 for selecting the store. Just allow it to automatically select the store (the default) and click Next.

Figure 3

5. You will then just see the summary as shown in Figure 4, click Finish.

Figure 4

6. You should now have a publisher certificate installed into your personal certificate store that contains both the public and private keys for the same certificate. Now you need to export it to a .pfx file that you can back up and use on other machines. Open certmgr by running certmgr.exe from a Visual Studio 2005 command prompt (see Figure 5).

Figure 5

7. Find the certificate you just imported (by publisher name) in the list in the Personal tab (selected by default). Press the Export button.
8. The first step of the export wizard will be presented (see Figure 6). Press Next.

Figure 6

9. The next step asks whether you want to export the private key. If you are generating a pfx file for ClickOnce deployment, the answer here must be yes, which is not selected by default (see Figure 7). Press Next.

Figure 7

10. The next step asks what export file format you want, the default is fine (see Figure 8). Press Next.

Figure 8

11. The next step asks for a password to protect the pfx file that will be output, use a secure password and be careful who you give it to because this is the last line of defense if someone is able to get their hands on your physical pfx file to prevent them from being able to use it. Enter a password twice and click Next (see Figure 9)

Figure 9

12. The next step has you enter the path to the output file. You can press the browse button and navigate to the desired folder and select the file format from the file type drop down, or you can just type in a path (see Figure 10). Press Next.

Figure 10

13. You will see the summary screen, press Finish to generate the file (see Figure 11).

Figure 11

14. You will see a message box showing that the export was successful (see Figure 12).

Figure 12

At this point you now have a pfx file that you can point to with your Visual Studio project Signing tab properties to sign your ClickOnce manifests. You can share that file with other trusted members of your team and they can use it to sign your applications to put them into production.

Just realize that anyone who gets their hands on that file and knows or can guess the password will be able to sign and publish applications that look like they come from you, so you need to treat those files (particularly the pfx and pvk) very carefully.

It was a crazy week at TechEd last week. So crazy, no time to write or consume blogs. I gave two breakout sessions (Real World ClickOnce and Windows Forms: Build Enterprise Ready Forms Applications) and a Birds of Feather session (Windows Workflow Foundation).

You can get the slides and demos from the sessions here:

Real World ClickOnce:  Slides   Demos

Windows Forms: Build Enterprise Ready Forms Applications:  Slides   Demos

For the students from my 3 day WCF course and 2 Day WF course this week, or for anyone else who wants the code with out the supporting delivery, here you go.

For those who attended, it was good working with you this week!

WCF Course Demos and Lab Code

WF Course Demos and Lab Code

Julie Lerman has a nice post about creating a desktop icon as part of a ClickOnce install - a fairly common question / request, and very representative of the kinds of "custom" things people would like to be able to do as part of a ClickOnce installation.

There were specific discussions about the option to create a desktop icon in some design reviews in Redmond I took part in several years ago. If I remember correctly, that one was dismissed mostly because it is discouraged to add desktop shortcuts as part of an install, especially without prompting the user to let them choose.

But part of this kind of desire really comes back to understanding the trust model of ClickOnce in general.

The trust issues of ClickOnce are twofold:
1. ClickOnce should not make any modifications to the local machine at install time that could affect other applications or data on the machine.
2. ClickOnce should provide runtime protections to avoid allowing the application to do harm to the local machine.

For #1, this means that you cannot install things to the GAC, add things to the registry, put things in specific places in the file system, etc. Any of those things could affect other apps and users on the machine, which means that administrators are not going to trust low-privilege users to perform ClickOnce installs. As a result, the model will not get adopted in enterprise environments, which is the primary target environment for ClickOnce - to replace those darn intranet web apps that companies create for ease of maintenance with smart client apps that give the user a better experience but are just as easy to maintain because of ClickOnce.

So the bottom line for #1 is that the only forms of customization you have available to you directly through ClickOnce is specifying:

- Whether the app is available offline (meaning you get a Start menu item and an Add or Remove Programs item)

- When updates checks will occur

- What the publisher name is - which sets what the program group in the Start menu is

- What the application name is - which sets the name of the program in the Start menu and Add or Remove Programs

- What the application icon is - through the Visual Studio application settings, and used for the icon in the Start menu item and Add or Remove Programs

There are a number of other assorted options you can set through the Publish tab, but they all really affect how the publication and deployment occurs, but none are in the form of explicit control over what goes where.

For #2 - You specify what runtime permissions the application will have as part of its publish settings (through the Security tab in VS), which end up as a list of required permissions in the application manifest. If those permissions exceed what the application would be granted by Code Access Security at runtime based on the zone of the launch URL (Internet, LocalIntranet, MyComputer, TrustedSites, or RestrictedSites), then the permissions have to be elevated either through user prompting (the default, ClickTwice experience) or through the trusted publishers capability of ClickOnce.

The fact is that you can overcome or workaround any limitations caused by #1 by exploiting #2. If you request full trust for your application, code in your application can do whatever you want it to do when your application first starts up. However, this requires one big assumption - you are also assuming the user who is running your application has sufficient privilege to do whatever it is that your code will try to do. This violates one of the goals of ClickOnce - to provide a deployment mechanism that can be used by low privilege users. So if you write some custom code in your app that tries to create a registry key - your app will have to have Registry permission through ClickOnce, and the user will have to have permission to create a key wherever your app is trying to create it.

As Julie points out, to create the Desktop icon with your own code, the user doesn't need any special permissions because anyone can add a shortcut to their own desktop, but you will need several high trust permissions including unmanaged code execution, which basically means most people will just elevate the application to full trust to get it done. Elevating to full trust is definitely something to avoid if you can.

The recommended way of addressing a lot of scenarios that would require high-privilege custom startup code is to create those things through the Bootstrapper as a prerequisite. A desktop icon is not really a good candidate for that, but pre-deploying something like GAC components is. Making something a prerequisite may allow you to avoid requiring full trust for your application.

However, the dirty little truth about Full Trust is that even though you should always try to avoid jumping all the way to full trust, there are many things that you will likely need to do in any meaningful ClickOnce app that will require you to go to full trust. Examples include:

• Using the ClickOnce API ApplicationDeployment class for just about anything, such as checking if this is the first run of a given version to execute your custom code, or to perform on demand updates.
• Using WCF for remote communications
• Using Windows Workflow in your Windows Forms application

One way to add protections back into your application even if you do have to request full trust for the application as a whole is to have sections of code where you restrict permissions below that level. You can do this through Code Access Security IStackWalk modifiers to Deny certain permissions or PermitOnly certain permissions. You can do this to bracket out a section of code (for example where you call out to some third party component to make sure that they are not doing something like reading/writing from your disk or sending information over the web for data /intelligence collection purposes). The details for doing this are too involved for this post, but I do cover it in my upcoming ClickOnce book and the underpinnings from a CAS perspective are covered well in my colleague Juval Lowy's Programming .NET Components, Second Edition.

I was working with Paul Sheriff of PDSA this week to ClickOnce deploy a reporting tool we use for the Regional Directors program. We ran into a problem where we got the following error when we tried to publish:

The resolution was to obtain the correct version of the CAPICOM.dll, drop it into the \SDK\bin directory where the SignTool.exe lives (C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin with a default VS install), and then register the library with Regsvr32.exe). Since it is a COM library for the CryptoAPI, it can actually live anywhere on your machine once it is registered.

Not sure how this was not there on the machine in question, it normally gets installed and registered when you install VS according to the ClickOnce product team folks.

If you haven't stumbled on the top link on the MSDN homepage in the last 24 hours... WinFX Beta 2 is out. Finally some fresh bits that are synced up between WCF, WPF, and WF.

There is also a Go-Live license associated with all the bits, so you can get the jump on the competition by putting apps into production right away with WinFX capabilities. If you haven't started looking at WinFX capabilities yet, now is definitely the time. One good way to do so is to attend our WCF Master Class. You can find more details at http://www.idesign.net/.

You can get all the download bits for WinFX Beta 2 here: http://msdn.microsoft.com/windowsvista/downloads/products/getthebeta/

A common question with respect to ClickOnce is how to take an application that you have published and tested on your local machine or a local development server and move that application into production. The steps involved are not particularly complex, but do involve using some other tools to get it done and are not easy to figure out on your own unless you have a solid understanding of ClickOnce manifests, signing, and how they relate to the launch mechanisms of ClickOnce.

A key pre-requisite for doing this is that the administrator who will be placing the application on the target machine will need to have the publisher certificate that will be used to sign the production application available. Usually in large organizations the developers will not have access to the company's real certificate to do their development anyway, it will be up to the IT Administrator to get that certificate and do the final signing of the applications anyway.

Step 1: Move your application files to the target machine.
Assuming you have published your application with Visual Studio to your local machine or another test server in your development environment, the application files are contained in the virtual directory or folder that you specified as the Publish Location within Visual Studio. The deployment manifest, Bootstrapper setup.exe, publish.htm deployment page, and version specific deployment manifests are located in the root folder. For each version you published to that location, there is a subfolder that contains the application manifest and application files for that version. You might do this by zipping up the appropriate files and folders and just giving the zip file to the administrator who will put it into production.

To move the current version into production, you will need to copy the deployment manifest, setup.exe, version-specific manifest and sub-folder for the version you want to publish to the target machine deployment folder. You only need to include the publish.htm file if you intend to use that test page directly to expose the application to end users. But if you are going to put a link to the deployment manifest in some other page or send a link via email, you don't need to include the publish.htm page.

Step 2 (Optional): Make needed changes to application files
If you need to change something in the application files, such as changing a setting in the application configuration file or updating some graphics files, you will need to update the application manifest after modifying the application files themselves. So make the modifications needed in your application files.

Step 3: (Only needed if you did step 2): Update the application manifest file list
If you made any changes to any application files, you will need to refresh the list of files contained in the application manifest. This is because the manifest contains the hash for each file that provides a unique representation of the contents of the file. If you changed the application file, the hash for that file that is in the application manifest is no longer valid and needs to be updated.

- Open the application manifest (.manifest file in the application files folder for the version you are publishing) with mageui.exe.
- Select the Files category in the list on the left side of the window.
- Enter the path to the application files folder for the deployment on the right side.
- You can press the ellipses (...) button to browse to the folder.

This step does not have to be done on the target machine because only relative paths are stored in the manifest from the location of the manifest, but the manifest and the application files need to be located with the same relative folder path as they will be on the target machine (usually the same directory).
- After you have entered the path to the folder, press the Populate button.
-You will be prompted with a warning dialog about the fact that the files will be renamed with a .deploy extension.
- Click Yes in this dialog.

Step 4: Sign the application manifest
If you make any changes to the application files and update the application manifest as described in step 3, or if you just need to re-sign the application manifest with a production certificate that is different than the one that was used in development, then you will need to sign the manifest with Mage. To do so:
- Open the .manifest file with mageui.exe if not already open from step 3.
- Press the Save button in the toolbar, and you will be presented with the signing dialog shown below.

- Provide the path to the certificate file and the certificate password at the top of the dialog, or select the certificate from your personal certificate store at the bottom of the dialog.
- Click OK to sign the manifest with the selected certificate.

Step 5: Update the application manifest reference in the deployment manifest
If you performed step 4 and signed with a different certificate than the one used to
originally generate the deployment manifest, you now need to update the application reference in the deployment manifest. The application reference is a strong reference to the application manifest from the deployment manifest, including path information as well as the public key token from the digital signature in the application manifest. That signature is generated using the publisher certificate, so if you change the certificate, you have to update the application reference.

To update the application reference, do the following:
- Open the deployment manifest (.application file) in mageui.exe
- Select Application Reference from the list of categories on the left of the window
- Press the Select Manifest... button and navigate to the application manifest (.manifest file) for the version that you are deploying.

Step 6: Update the Deployment Provider
If you are moving the application to a different server than the one where you first published the application from Visual Studio, you will need to update the deployment provider URL that is embedded in the deployment manifest. To do so, perform the following steps:
- Open the deployment manifest in mageui.exe if it is not already opened from step 5.
- Select Deployment Options from the list of categories on the left side of the window.
- Change the URL labeled Start Location to reflect the URL users will use to launch the application from the client machine. This setting is saved as the deployment provider in the deployment manifest.

Step 7: Sign the deployment manifest
- Click the Save button in the toolbar.
- Enter the path and password for the publisher certificate file at the top of the signing dialog, or select the certificate from the list of certificates at the bottom. This should be the same certificate used to sign the application manifest.
- Click OK to re-sign the manifest.

At this point, your application should be ready to go from the client.

I gave four talks at the Software Developers Conference in Netherlands this week. This is a very fun and interesting conference that is put on by a large user group organization called Software Developers Network, run by Remi Caron and Joop Pecht.

This conference is one of the most enjoyable conferences I get to do anywhere in the world. It is amazing how professional and well run this conference is, especially when you consider that it is being put on by a user group organization and it is better run than many U.S. conferences put on by companies that are supposed to specialize in this kind of event. All of the user group members that run the conference are volunteers, and yet the quality and professionalism that comes out of that is outstanding.

The attendees are hard core, ask great questions, and make the event fun for the speakers as well. For those of you who attended and find your way to this post for the slides and demos - thanks!

You can grab the slides and demos here:

Build Smart Client Data Apps with Windows Forms 2.0:  Slides   Demos
Build Custom Data Bound Objects and Collections:  Slides   Demos
Present Rich Tabular Data with the DataGridView Control:  Slides   Demos
Drive Application Behavior with Application and User Settings:  Slides   Demos

I spoke at DevTeach  in Montreal Tue-Thu of this week and had a great time as always. If you haven't checked out this conference, you should plan on signing up next year. Great location, great speakers, very well done conference with lots of hard core sessions.

If you attended one of my sessions and want to get the slides and demos, here you go:

NET371 - Drive App Behavior with Application and User Settings:  Slides   Demos

NET391 - Custom Bound Objects and Collections:  Slides   Demos

NET463 - Advanced ClickOnce:  Slides   Demos

MusicLibrary Database Creation Script:   Script

I taught a public Advanced .NET Master Class in Reston VA last week. Had a great time, great bunch of students. One of the things that makes teaching the most fun is answering questions, and this was a lively group with the questions. Thanks to all of the students who attended.

A lot of the demos that I give during class are part of the downloads available on our site at http://www.idesign.net. If you want the live demos that I did on the fly, you can download them here:

Live Demos

We will be running a Code Camp at the Microsoft Reston training center on 10 June all day. This is a great FREE event with great speakers teaching you hard core topics on .NET coding. We are looking for speakers, so if you are interested in sharing your knowledge with the local community, you can find the call for speakers here as well as registration information if you just want to attend and soak up knowledge.

Come on out and participate in the DC area developer community!

People always ask me "How can you write a whole book on ClickOnce?" because they envision the standard 5 minute demo of what ClickOnce is and does and think that is all there is to it. The fact is there is just a plethora of variations, hidden behaviors, specialized scenarios, and things people want to do with ClickOnce that are far more than 5 minute answers. The book keeps growing the more I get into it.

One of these things that snuck up and bit me recently (unfortunately in a live demo at VS Connections) due to a gap in my knowledge was the way partial trust apps run on the client machine.

First some background on ClickOnce and application files. Any file you add to your project and set the file Build Action property to Content will be added to the Application Files (under the Publish tab in project properties) with a Publish Status of Include, depending on the file type. MDF files (SQL Express), mdb, and XML files will get marked as Data Files instead of Include. Include means the file will be deployed to the application client cache folder under the user profile (C:\Documents and Settings\<username>\Local Settings\Apps\<obfuscated goo>\), and Data File means it will be deployed to a separate data folder associated with that app, also buried in the obfuscated goo under the user profile. The data files are treated differently for updates (beyond the scope of this post) and the folder is accessible through the ApplicationDeployment.DataDirectory property.

If you deploy an app with ClickOnce, and the app manifest requests Full Trust, then when the app runs it simply gets launched by the runtime directly - the app executable is the executable process that runs. It runs from the deployed client cache directory. As a result, with a full trust app, you can access files that you deploy with your app, marked with a Publish Status of Include, with a relative path such as ".\MyImage.jpg". The current working directory when your executable starts is the folder it was launched from, and so everything works out.

Then you decide that you want to be more security concious, and switch your ClickOnce security settings to only require partial trust (lets say LocalIntranet zone). Suddenly your app stops working complaining that it can't find the file.

So what's going on there??

The problem is that the executable process is actually different when you run a ClickOnce app under partial trust. When you configure a ClickOnce deployed app to request less than full trust, the process that actually launches is AppLaunch.exe. This process loads your executable assembly into an AppDomain which it has cranked down the CAS security on to your requested permissions, and your app runs from that appdomain under partial trust. This is similar to what Visual Studio 2005 does to enable partial trust debugging with the <appname>.vshost.exe that is the debug process by default.

So how does that screw up your paths? AppLaunch.exe is running from the .NET directory under C:\WINDOWS\Microsoft.Net\Framework\v2.0.50727\, and so the current working directory for your app loaded into that host process is that folder. Naturally your application files have not been deployed there, so your relative paths for locating the files fail.

OK, so next thought is "there's gotta be an API that I can call to say 'give me my app's deployed directory'". Unfortunately, that thought would be incorrect.

So what's the solution? Simple - don't ever deploy a file to the application directory (Publish Status = Include) that you need to access explicitly through a path (i.e. to load that file as a bitmap, xml file, etc.). If you need to do that, you should mark it as a Data File, and access it by adding the file name to the ApplicationDeployment.DataDirectory path. You can also use Application.UserAppDataPath property, results in the same thing when you are ClickOnce deployed.

Just wish I had known that before doing that demo on the fly in a way I had not done it before in front of a live audience... :)

I presented four sessions at DevConnections last week and have been a little remiss on getting the slides and demos posted, but here they are:

Secure ClickOnce Deployments:  Slides   Demos

Connecting Smart Clients with WCF: Slides   Demos

Drive Application Behavior with User and Application Settings:  Slides   Demos

Build a Data Access Layer with Enterprise Library Data Access Block:  Slides  Demos

If you didn't happen to notice it in your Visual Studio Start page RSS feed, this is very cool. They have put out a very comprehensive Code Snippets library for C#, available here:

http://msdn.microsoft.com/vstudio/downloads/codesnippets/default.aspx

When I teach our Master Class or Advanced Master Class at IDesign, I often get the question of why Visual Basic has a ton of code snippets and why C# only has a couple dozen. I always feel like I am apologizing for the C# team or it is tempting to make a joke at the VB guys's expense and say they need them more, which I really don't believe but is usually got for a laugh (or a few death threats from the VB guys). :)

The fact is we C# guys need them just as bad and should use Code Snippets and other forms of Code Generation such as CodeRush and CodeSmith to the max. Resources like www.gotcodesnippets.com help a lot for not always needing to create one from scratch for every specialized situation you find yourself repeating, but this library gets us even closer with somewhat "out of the box" capabilities.

It includes all kinds of code snippets from collections, to data access to creating data types, cryptography, security, and Windows Forms common needs. These can not only help you avoid writing repetitive code over and over, they give you completed code samples for a lot of situations where you may not have ever written that kind of code before.

Thanks to whoever created this at Microsoft!

I gave a talk on Data Binding with Windows Forms 2.0 at the San Diego .NET Developers Group on Tuesday 7 Mar.

Here are the slides and demos:  Slides   Demos

I gave a talk on Connecting Smart Clients at the Microsoft Integration and Connected Systems User Group (MICSUG) last night. I discussed and demoed the basics of using Windows Communication Foundation (WCF) to connect applications, using the newly released Feb CTP.

You can get the slides and demos here:  Slides   Demos

In jumping through the hoops yesterday to get my demos running on the Feb CTP, there were a number of changes that I had to get used to compared to previous builds.

The biggest is that if you run svcutil against a service that uses wsHttpBinding to generate a proxy, you get a proxy service contract that uses custom message contracts to wrap the parameters and return values from each operation contract. XXXRequest and XXXResponse classes are defined in the proxy file for each operation, along with an XXXBody class that actually contains the raw parameter/DataContract types.

If you program against the service contract interface like so:

IAccountsManager mgrProxy = new AccountsManagerProxy();

You will have to create the XXXRequest message contract types to wrap all the parameters you pass into the methods, and unwrap any return values from the XXXResponse types. However, they also expose a public method on the proxy class directly that encapsulates these details so that you can deal directly with the underlying parameters and return values.

So instead of calling IAccountsManager.GetAllAccounts for example, you will have an easier time calling AccountsManagerProxy.GetAllAccounts.

This is true for wsHttpBinding because of the message level security involved in the default binding. If you use basicHttpBinding, or turn down the security on the wsHttpBinding, then you will get more straightforward service contract interface definitions on the client side proxy.

The resulting proxy and service contract look like the following:

[System.ServiceModel.ServiceContractAttribute()]

{

// CODEGEN: Generating message contract since message part accountNo requires protection.

[System.ServiceModel.OperationContractAttribute(Action= "http://tempuri.org/IAccountsManager/CreateAccount", ReplyAction="http://tempuri.org/IAccountsManager/CreateAccountResponse" )]

CreateAccountResponse CreateAccount(CreateAccountRequest request);

// CODEGEN: Generating message contract since message part GetAllAccountsResult requires protection.

[System.ServiceModel.OperationContractAttribute(Action= "http://tempuri.org/IAccountsManager/GetAllAccounts", ReplyAction="http://tempuri.org/IAccountsManager/GetAllAccountsResponse" )]

GetAllAccountsResponse GetAllAccounts(GetAllAccountsRequest request);

// CODEGEN: Generating message contract since message part fromAccountNo requires protection.

[System.ServiceModel.OperationContractAttribute(Action= "http://tempuri.org/IAccountsManager/Transfer", ReplyAction="http://tempuri.org/IAccountsManager/TransferResponse" )]

TransferResponse Transfer(TransferRequest request);

}

[System.CodeDom.Compiler.GeneratedCodeAttribute( "System.ServiceModel", "3.0.0.0")]

{

}

[System.CodeDom.Compiler.GeneratedCodeAttribute( "System.ServiceModel", "3.0.0.0")]

{

public AccountsManagerProxy()

{

}

public AccountsManagerProxy(string endpointConfigurationName) :

base (endpointConfigurationName)

{

}

public AccountsManagerProxy(string endpointConfigurationName, string remoteAddress) :

base (endpointConfigurationName, remoteAddress)

{

}

public AccountsManagerProxy(string endpointConfigurationName, System.ServiceModel.EndpointAddress remoteAddress) :

base (endpointConfigurationName, remoteAddress)

{

}

public AccountsManagerProxy(System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress remoteAddress) :

base (binding, remoteAddress)

{

}

CreateAccountResponse IAccountsManager.CreateAccount(CreateAccountRequest request)

{

return base .InnerProxy.CreateAccount(request);

}

public void CreateAccount(int accountNo, string name, decimal initialBalance)

{

CreateAccountRequest inValue = new CreateAccountRequest();

inValue.Body = new CreateAccountRequestBody();

inValue.Body.accountNo = accountNo;

inValue.Body.name = name;

inValue.Body.initialBalance = initialBalance;

CreateAccountResponse retVal = ((IAccountsManager)( this )).CreateAccount(inValue);

}

GetAllAccountsResponse IAccountsManager.GetAllAccounts(GetAllAccountsRequest request)

{

return base .InnerProxy.GetAllAccounts(request);

}

public BankingBusinessLayer.Account[] GetAllAccounts()

{

GetAllAccountsRequest inValue = new GetAllAccountsRequest();

inValue.Body = new GetAllAccountsRequestBody();

GetAllAccountsResponse retVal = ((IAccountsManager)( this )).GetAllAccounts(inValue);

return retVal.Body.GetAllAccountsResult;

}

TransferResponse IAccountsManager.Transfer(TransferRequest request)

{

return base .InnerProxy.Transfer(request);

}

public void Transfer(int fromAccountNo, int toAccountNo, decimal amount)

{

TransferRequest inValue = new TransferRequest();

inValue.Body = new TransferRequestBody();

inValue.Body.fromAccountNo = fromAccountNo;

inValue.Body.toAccountNo = toAccountNo;

inValue.Body.amount = amount;

TransferResponse retVal = ((IAccountsManager)( this )).Transfer(inValue);

}

}

I recorded a DNR and DNRtv last week in New London and they are already up on the site.

You can download/listen to the .NET Rocks! epsidode here: http://www.dotnetrocks.com

And the DNRtv here: http://www.dnrtv.com

In the DNR episode, we talk about data binding, ClickOnce and a few other related topics.

This DNRtv shows how to do some of the data binding stuff in the designer. Keep your eyes out for another episode in a week or so on ClickOnce deployment.

Here is a little trick that has bitten me on more than one occasion, and just bit someone who attended my data binding session in NYC the other night.

Here is the setup to be bitten by the defaults in Visual Studio:

- Add a SQL Express database to your project

- Edit the schema, add some tables, etc.

- Write some code / data binding that uses the database

- Run a debug session adding records or modifying ones you created through the designer.

- Save the changes from your running debug session.

- Shut down the app and run another debug session, and your changes are no longer there.

First instinct at this point is "there is something screwed up with my data binding / data access code". That instinct may be wrong (although we are all good at writing bugs as well).

When VS adds the MDF file to your project, it places it and its related LDF file in the project root folder, and add them to your project in solution explorer. The file properties for the MDF file include Build Action = Content, and Copy To Output Directory = Copy Always.

What is happening is that your changes are being persisted to the copy of the MDF file that was placed in your build output directory (bin\debug) on the first debug run. Then on the second debug run, the unchanged MDF file from the project root folder is copied down into the build output folder, overwriting the one that was there with your changes from the previous run. As a result, it looks like your changes were not persisted when in fact they were (or may have been if your code was correct).

The solution is that whenever you add a SQL Express DB to your VS project, you probably want to change the Copy To Output Directory property for the file to Copy If Newer.

I gave a talk on data binding in NYC this Thu night. Had a great time. Lively crowd as always, lots of good questions and interaction.

Here are the slides and demos:

Slides    Demos

I gave a presentation on WPF last night in Orlando to ONETUG. Great group, lots of good questions, had a lot of fun.

Here are the slides and demos:  Slides   Demos

A couple people have suggested that I post the table of contents for my book to my blog since it is not yet available on Amazon.

Here it is:

Foreword xxi

Preface xxiii

Acknowledgments xxxv

About the Author xxxvii

Chapter 1: Building Data-Bound Applications with Windows Forms 1

What Is Data Binding? 2

Your First Data-Bound Windows Forms 2.0 Application 3

Data-Binding Landscape 14

Data Sources 15

Data Objects and Collections 16

DataSets or Not, That Is the Question... 18

Data-Bound Controls 20

Layered Application Architecture 21

What Is a Smart Client? 27

Where Are We? 28

Chapter 2: Working with Typed Data Sets and Table Adapters 31

A Quick Review of DataSets 31

The Quest for Type Safety 34

Typed Data Set Internals 37

Creating Typed Data Sets 41

Creating Typed Data Sets with the Data Set Designer 42

Typed Data Set-Generated Code 49

Introduction to Table Adapters 52

Filling and Updating a Typed Data Set with a Table Adapter 56

Connection Management 58

Adding Transaction Support to a Table Adapter 62

Adding Helper Data Access Methods 66

Basing Table Adapters on Stored Procedures or Views 67

Adding Queries to Table Adapters 69

Creating Typed Data Sets with Command Line Tools 77

Using Typed Data Sets in Your Code 78

Where Are We? 79

Chapter 3: Introducing Data Binding in Windows Forms 81

The 40,000-Foot View of Data Binding 81

Binding Data Collections to a Grid 86

Binding Data Collections to Multi-Valued Controls 88

Binding Data to Individual Controls on a Form 90

Data Paths Within Data Sources 92

Synchronizing Data Between Controls 96

Smarter Data Containment 97

Paging Through Data 99

Master-Details Data Binding 104

Updating Data Sources Through Data Binding 106

Where Are We? 108

Chapter 4: Binding Controls to Data Sources 111

Getting to Know the BindingSource Component 111

Simple Data Binding with Binding Sources 112

Chaining Binding Sources for Master-Details Data Binding 116

Navigating Data Through a Binding Source 121

Manipulating Data Through a Binding Source 122

Using a Binding Source as a Data Storage Container 124

Filling a Binding Source with a Data Reader 126

Sorting, Searching, and Filtering Presented Data with a Binding Source 128

Monitoring the Data with Events 131

Restricting Changes to the Data 133

Underneath the Covers of Data Binding for Complex Types 134

Binding an Image Column to a PictureBox Control 141

Binding a DateTime Column to a DateTimePicker 142

Binding a DateTime Column to a TextBox 144

Binding a Numeric Column to a TextBox 145

Automatic Formatting and Parsing Summary 147

Going Beyond Built-In Type Conversion with Binding Events 148

Handling the Format Event 154

Handling the Parse Event 156

Completing the Editing Process 157

Making the User’s Life Easier with AutoComplete 160

Data Binding Lifecycle 162

Smarter Child-Parent Data Binding 163

Binding to Multiple Copies of Data 165

Updating Parent Data-Bound Controls from Child Data-Bound Controls 168

Synchronizing Many-to-Many Related Collections 172

Where Are We? 176

Chapter 5: Generating Bound Controls with the Visual Studio Designer 177

Working with the Data Sources Window 177

Adding Data Sources to a Project 179

Choosing the Type of Data Source 180

Adding a Database Data Source 181

Adding a Web Service Data Source 185

Adding an Object Data Source 186

Generating Bound Controls from Data Sources 189

Selecting the Bound Control Type 196

Customizing the Bound Control Types 196

Binding Existing Controls to Data Sources 199

Behind the Scenes: Designer Code and Data Sources Files 202

Other Designer Data-Binding Code Generation 205

Setting Control Data Binding Through the Properties Window 206

Generating Data Bindings with Smart Tags 210

Generating Master-Details Data-Bound Controls with the Designer 214

Where Are We? 216

Chapter 6: Presenting Data with the DataGridView Control 217

DataGridView Overview 218

Basic Data Binding with the DataGridView 219

Controlling Modifications to Data in the Grid 221

Programmatic DataGridView Construction 222

Custom Column Content with Unbound Columns 226

Displaying Computed Data in Virtual Mode 233

Using the Built-In Column Types 241

Built-In Header Cells 255

Handling Grid Data Edits 256

Automatic Column Sizing 259

Column and Row Freezing 262

Using the Designer to Define Grids 263

Column Reordering 266

Defining Custom Column and Cell Types 269

Utilizing Cell-Oriented Grid Features 277

Formatting with Styles 281

Where Are We? 284

Chapter 7: Understanding Data-Binding Interfaces 285

What Does Data Binding Have to Do with Interfaces? 286

The IEnumerable and IEnumerator Interfaces: Supporting Iteration Through Collections 289

The ICollection Interface: Controlling Access to a Collection 295

The IList Interface: Enabling Data Binding 298

The IListSource Interface: Exposing Collections of Collections 303

Property Descriptors: Allowing Dynamic Data Item Information Discovery 305

The ITypedList Interface: Exposing Data-Binding Properties 307

The IBindingList Interface: Providing Rich Binding Support 310

The IBindingListView Interface: Supporting Advanced Sorting and Filtering 323

The ICancelAddNew Interface: Supporting Transactional Inserts in a Collection 325

The IRaiseItemChangedEvents Interface: Providing Item Modification Notifications on Collections 327

The IEditableObject Interface: Supporting Transactional Item Modifications 328

The INotifyPropertyChanged Interface: Publishing Item Change Notifications 329

The ICustomTypeDescriptor Interface: Exposing Custom Type Information 332

The ISupportInitialize Interface: Supporting Designer Initialization 334

The IDataErrorInfo Interface: Providing Error Information 330

The ISupportInitializeNotification Interface: Supporting Interdependent Component Initialization 337

The ICurrencyManagerProvider Interface: Exposing a Data Container’s CurrencyManager 341

Where Are We? 341

Chapter 8: Implementing Custom Data-Bound Controls 343

Extending Framework Data-Bound Controls 344

Creating a Grouped Column DataGridView 345

Using Custom Controls 350

The User Control Test Container 352

Developing Data-Bound Container Controls 353

Building a Filtered Grid Control 354

Adding Data-Binding Capability to a Custom Control 357

Supporting Designer Initialization of Data Binding 359

Specifying Binding Properties on a Control 360

Supporting Delayed Initialization with ISupportInitialize 362

Dynamically Determining the Properties of a Data Source 367

Autocompleting Input in a TextBox Control 371

Autosizing Columns in the Grid 375

Winding Up the Filtered Grid Example 376

Building a Custom Data-Bound Control from Scratch 379

Building a Data-Bound Charting Control for Decision Support 379

Coding a Data-Bound Custom Control 384

Adding Editing Support to a Custom Data Bound Control 391

Where Are We? 397

Chapter 9: Implementing Custom Data-Bound Business Objects and Collections 399

Defining and Working with Data-Bound Business Objects 400

Defining and Working with Data-Bound Business Object Collections 405

.NET Framework Generic Collection Classes 406

The CustomBusinessObjects Example 408

Setting the Textual Data-Binding Behavior of Custom Objects 415

Supporting Transacted Object Editing with IEditableObject 416

Supporting Object Edit Notifications with Property Change Events 420

Supporting Object Edit Notifications with INotifyPropertyChanged 423

Using BindingList<T> to Create Rich Object Collections 424

Creating a Custom Collection Type Based on BindingList<T> 426

Managing Transacted Additions to a Collection 439

Raising Item Changed Events 441

Adding IBindingListView Functionality 443

Binding to Business Objects Through the Data Sources Window 453

Where Are We? 455

Chapter 10: Validating Data Input and Handling Errors 457

Windows Forms Validation 458

Handling Validation Events 459

DataGridView Validation Events 462

Validation Up the Control Hierarchy 463

Displaying Validation Errors with the ErrorProvider Control 464

DataGridView Error Displays 467

DataGridView DataError Event 468

Controlling Validation Behavior with the AutoValidate Property 471

Validation down the Control Hierarchy 472

Extended Validation Controls 474

Capturing Data Errors on Data Sets 475

Providing Error Information from Custom Objects with IDataErrorInfo 479

Data Concurrency Resolution 483

Where Are We? 484

Appendix A: Binding to Data in ASP.NET 487

ASP.NET Page Processing Basics 489

Data Binding in ASP.NET 1.X 490

Data-Binding Overview in ASP.NET 2.0 498

Data Sources 499

Data-Binding Expressions 508

GridView Control 509

DetailsView Control 512

FormView Control 514

Master-Details Binding 515

Hierarchical Binding 518

Where Are We? 519

Appendix B: Binding Data in WinFx Applications 521

WinFx UI Programming and Capabilities Overview 522

Writing a Simple WinFx Application 525

WinFx Data Binding 101 532

Data Contexts and Data Sources 536

What About XAML? 537

Binding a Collection to a Grid with Templates 541

Control Styling in WinFx 543

Where Are We? 545

Appendix C: Programming Windows Forms Applications 547

Your First Windows Forms Data Application 548

Creating Windows Forms Applications with Visual Studio 554

Windows Forms Designer-Generated Code (New in 2.0) 563

A Brief Tour of the Windows Forms Architecture 567

The Dawn of .NET Execution—The Main Method 570

Handling Control Events 574

Displaying Other Forms 576

Containing Forms Within a Parent Form 577

Common Data Display Controls 578

Creating a Custom User Control 586

Laying Out Controls on a Form 589

Setting Tab Order 596

Command and Control of Your Windows Forms Applications (New in 2.0) 598

Where Are We? 600

Appendix D: Accessing Data with ADO.NET 601

Relational Data Access 603

The Ubiquitous DataSet 607

Loading Data Sets from a File 609

Creating a Data Set Programmatically 611

Loading Data Sets from a Database 613

Loading a DataTable with a DataReader 619

Master-Details DataSets 621

Retrieving Data with Stored Procedures 623

Updating the Database Using Data Sets 624

Handling Concurrency 628

Updating with Data Sets and Stored Procedures 632

Searching Data Sets 637

Merging Data from Multiple Data Sets 639

Working with Data Views 641

Working with Transactions 643

Scoping Transactions with System.Transactions 647

Client-Side Transactions 650

Data Set and Data Adapter Events 651

Reading Data into Business Objects 654

XML Data Access 658

Working with the XmlDataDocument Class 659

Working with the XPathDocument Class 663

Loading Data into an XPathDocument 664

Querying XML Data 665

Navigating an XML Document 667

Where Are We? 670

Index 671

I gave a talk on data binding at the Sarasota FL .NEt Users Group last night. Had a great time, and it was especially fun to present this topic this time since it was the first time presenting on data binding since my book came out. Gave away a couple copies. It was also great to go have some beers with the group members afterwards, including fellow MVPs Stan Schultes and David Hayden.

You can grab the slides and demos here:  Slides   Demos

It was a very cool feeling to have a box of my books delivered to me on Friday. After starting way too early on it and rewriting many of the chapters multiple times as the capabilities evolved in Visual Studio 2005 and .NET 2.0, it felt very good to finish the writing a couple months ago. But having the finished product show up on my doorstep was very cool.

So stop reading this and go buy one dammit! :)

I co-presented the Smart Client session at the DC Launch event yesterday at the Washington Convention Center with Marc Schweigert, a Microsoft Developer Evangelist for the Federal Sector. We covered a lot of good material on Windows Forms 2.0 capabilities including data binding and ClickOnce, two topics close to my heart since I have written/am writing books on them. I also spent most of the day in the Ask the Experts booth along with other local DC area experts like Sahil Malik, Randy Hayes, G. Andrew Duthie, Darrell Norton, Jonathan Cogley and Vishwas Lele. Besides being a great opportunity to catch up with all these guys and exchange ideas, it was a great day talking to developers from the area and seeing how much enthusiasm there is around the availability of VS 2005 and .NET 2.0. Most of the people there had spent little to no time looking at the new stuff, so there was the usual "wow!" reaction when they saw all the great features and capabilities that are now available to them.

I think we ended up with over 2000 attendees at the event, with about a thousand or so sticking around to the bitter end for our session, which was last up at 4:30-5:45.

The folks at Microsoft that put together the event (Darryl Schaffer in particular) did a great job organizing and running the event.

I posted all the sample code for my book Data Binding with Windows Forms 2.0 on the book Web site at http://www.softinsight.com/databindingbook. The samples are available in both C# and VB, even though all the code in the book is in C#. The book should be hitting the shelves very soon and is already selling well on Amazon.

I also posted instructions for running the samples if you do not have a non-default instance of SQL Server or don't have Northwind on your machine yet, also how to run the samples with SQL Server 2005 Express, Visual C# 2005 Express and Visual Basic 2005 Express.

Happy Data Binding!

A common requirement and question that is very easy to solve with the DataGrid is the need to have a column or columns in a grid that contain a drop down list of lookup values from a related table. For example, in Northwind, we have the Products table with a foreign key column SupplierID that relates the to Suppliers table. The values in the Suppliers table could be treated as a list of lookup values for editing the supplier associated with a product:

When a supplier is selected from the drop down list, it should set the SupplierID column value for that row in the products table. This is very easy to achieve through the Windows Forms designer and the smart tag for a DataGridView control.

Do the following to try it out:

1. Create a Windows Forms Project.
2. Add a data source to a data set that contains Products and Suppliers tables from the Northwind database. This could be any kind of Data Source (Database, Object, Web service), but for simplicity for trying out the designer, just use a database one which adds the typed data set into the Windows Forms project. Products is the table of data we will display in the grid, and Suppliers is the lookup table related through a foreign key column in the Products table that we want to display as a combo box of selectable values in the grid.
3. Drag and drop Products from the Data Sources window onto the form. This will generate the grid, a data set instance, a table adapter to fill it, a BindingSource component hooked up to the data set and the Products table within it, a grid hooked up to the products binding source, and a binding navigator hooked up to the binding source.
4. Click on the grid smart tag (little triangle on upper right border of control).
5. Select Dock in Parent Container.
6. Select Edit Columns.
7. Select the SupplierID column in the list on the left.
8. Select the ColumnType property and set it to DataGridViewComboBoxColumn.
9. Select the DataSource property and navigate down through the data source tree through Other Data Sources > Project Data Sources > NorthwindDataSet > Suppliers table.

10. Select the DisplayMember property and select CompanyName.
11. Select the ValueMember property and select SupplierID.
12. Click OK to close the Edit Columns dialog.
13. Run the app and observe that you get the drop down list of suppliers. Selecting a supplier actually changes the SupplierID column value for that row in the products table to the appropriate foreign key value.

You can download a completed sample that was generated with these steps here.

The question came up from several attendees at my MSDN Webcast on ClickOnce yesterday:

"Can I launch a XXX application using ClickOnce?" (fill in XXX with VB6, MFC, etc. - non-.NET applications)

The answer is yes, you will just have to employ a little trick.

What you need is a simple little launcher application that IS a Windows .NET application. So do the following:

1. Create a new Windows Application project with VS 2005.
2. Delete the Form1 from the project.
3. Add the unmanaged EXE and any supporting files to the VS 2005 project, which makes them part of this application from a ClickOnce perspective. As a result, they will get deployed with this application to its cache folder and can be executed by this launcher app.
4. Edit the Program.cs file Main method and delete the current method body (which launches the application and the form) and replace it with code to launch the unmanaged executable. This just requires a single line of code: Process.Start("MyUnamangedApp.exe");

Note: You will need to give the launcher app full trust in the ClickOnce security settings.

Note2: If the unmanaged app relies on ActiveX or COM objects, those need to be added to the project as well, and you will need to add a reference to the COM DLL's to the project to get their reg-free COM information added to the manifest. See this article for more details.

You can download a sample implementation here.

For those who attended or are interested, here are the demos from my MSDN Webcast on ClickOnce yesterday.

You can find the webcast link for on-demand viewing here.

For the demo that went awry demonstrating on-demand updates, the little mistake I made was that I said that if you turn off automatic updates (Check for updates option at top of Updates dialog), then you need to put in an Update location, which is true. But what I was doing was fully qualifying the path to the deployment manifest, which is incorrect. What you need to put is just the URL to the root folder where the deployment manifest resides. VS will automatically append the deployment manifest file name. So when I was putting in:

http://localhost/ClickOnceOnDemand/ClickOnceOnDemand.application

I should have just been putting

http://localhost/ClickOnceOnDemand/

Another little tidbit I didn't mention is that you will need Full Trust for on-demand updates, which is unfortunate because it means the app has to request full trust even though it may not be doing anything privileged beyond on-demand updates.

In previous builds of WCF (Indigo), you had to have a particular namespace included in your config file. Specifically, instead of the default root element of:

<configuration>
<!-- The rest of your config settings -->
</configuration>

You needed to have:

<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
<!-- The rest of your config settings -->
</configuration>

By doing that in previous builds, you got intellisense for the schema elements and attributes of the <system.serviceModel> element, letting you discover the right entries to get features like transactions, security, bindings and so on correctly configured.

When I installed the Nov CTP, I was immediately lost because my intellisense seemed to have gone away. If you add a WinFx Service from the Web Site templates, the web.config still has the namespace shown in the second config snippet above. But the trick is that it is no longer needed, and in fact confuses VS on what schema elements to expose through intellisense. The system.serviceModel schema elements are now merged with the C:\Program Files\Microsoft Visual Studio 8\Xml\Schemas\DotNetConfig.xsd schema as part of the VS extenstions install, so they are there by default now in the config file intellisense.

Thanks to my colleague Juval Lowy for discovering this fact and giving me back my intellicrack!

Here are the demos from my MSDN Webcast today on the DataGridView control.

You can find the sample DataGridView chapter for my book here.

You can view the webcast on demand through the links here.

I gave a talk on connecting smart clients with WCF on Tuesday at Boulder .NET. Had a good turnout desipte the proximity to the holiday and had a good time.

The talk covered the fundamentals of connecting applications with WCF since most of the people there had never seen anything on WCF. Then I moved into some of the specific client concerns when using WCF, similar to my talk at VSConnections.

You can get the slides and demos here:  Slides   Demos

For the students from my recent class in Sweden, you can download all the demos I did dynamically (as opposed to the ones you already have in your demos folder and available on our site at www.idesign.net) from the following link:

http://www.softinsight.com/downloads/Linsoft05ClassDemos.zip

I gave two WCF (Indigo) talks at DevConnections today:

Build Event Driven Applications with Indigo:   Slides   Demos

Connecting Smart Client Applications with Indigo:  Slides   Demos

In the Event Driven Applications session I cover creating list based subscription services with direct callback services in the clients, using duplex channels to set up callbacks, and a Pub-Sub implementation that gives loosely coupled events that I will have more information on here in the near future.

In the smart client session, I covered client concerns with respect to channel selection, asynchronous calls, sessions, transactions, callbacks, security, and peer-to-peer.

Good time!

I just got finished doing my first talk here at DevConnections in Vegas and I think it went pretty well. Great crowd, good questions, fun topic.

You can grab the slides and demos here: Slides   Demos

The talk highlighted how to define custom objects and collections to make them suitable for data binding, mostly for Windows Forms, but some of it is applicable to ASP.NET as well.

The key takeaways from the talk are:

• Implement INotifyPropertyChanged on any business entitity type you define that you expect to use in data binding scenarios. This interface defines a contract for the objects to raise PropertyChanged events whenever a property is set on the object. It allows containing collections or bound controls to be notified when the contents of the data object change, which helps with keeping controls synchronized in a form.
• Use BindingList<T> to create strongly typed collections of objects that support rich data binding. It provides full implementation of IList, ICollection, IEnumerable and their generic strongly typed counterparts for whatever type parameter you provide, and it provides a partial implementation of the IBindingList interface. The part that it implements is firing ListChanged events when items are added or removed from the collection. It also looks at the objects type that you provide as a type parameter, and if it implements INotifyPropertyChanged, the collection will subscribe to the PropertyChanged event on each object and raise ListChanged events with a change type of PropertyChanged whenever the contents of an object in the collection change. These features make BindingList<T> collections work seamlessly with data binding to multiple controls and keeps the controls all in sync.
• Use my BindingListView<T> class (in the demos and in my book) to get a generic container that supports sorting (both IBindingList based single property sorts and IBindingListView multi-property sorts), searching, and filtering.

If you were there at the end and saw the on-the-fly demo where I didn't see the saving behavior that I thought I had just implemented, I tracked down the problem. the changes were actually being saved. It was just the way I hooked up the data binding I wasn't seeing those changes.

In the demo, I used the data sources window to generate a Details view (control collection) bound to a collection of Album data. I changed one of the controls in the collection which was bound to a GenreID property on the Album objects to a ComboBox. I then used the Data Sources window to add data binidng to a Genre object collection to populate the list of Genres in the combo box. This sets up the ComboBox to have its contents determined by the Genre collection, but its SelectedValue property is bound to the GenreID property on the current item in the Album collection - generally exactly what you want to be able to edit a property on one object collection item through a lookup list of values in another collection of objects. The problem was that after I selected a new value in the combo box and saved the changes, then restarted the app, I wasn't seeing the modified value set for the Album I was viewing in the other controls.

It turns out the problem was just the order that I did the initial binding of the control collection and the combobox BindingSources. In the form load I had added the following two lines of code to bind the control collection and the combo box binding sources:

albumBindingSource.DataSource = Album.GetAlbums();
genreBindingSource.DataSource = Genre.GetGenres();

The problem is that when you set the DataSource, that is when it intializes the bound controls. So I was initializing the data bindings for all of the controls based on the album data, then intializing the combo box of Genres with a new set of data. That set the SelectedIndex of the ComboBox back to zero, so I wasn't seeing the actual value of the Genre for the current Album, I was just seeing the first Genre value in the Genre collection. The fix is simply to do the initial binding in the reverse order:

Enjoy!

I'm catching a flight early tomorrow morning to Vegas for VS Connections and am really looking forward to it. VS Connections in particular, and DevConnections in general (the overall conference event) is well run, in great locations, and always has a lot of great content that I can benefit from as well.

I've been spending most of my recent prep time fine tuning the demos for my two WCF sessions, Build Event Driven Applications with Indigo and Connecting Smart Client Applications with Indigo. The more I work with Windows Communications Foundation (aka "Indigo"), I am struck by a number of things:

• I am impressed by how capable Indigo is.
• I am awed by how elegant and simple solutions are to complex aspects like security, transactions, queuing, callbacks, and so on.
• I am dumbfounded by how hard it is to figure out how to get to those elegant and simple solutions.

The last bullet is not really a criticism of what they have come up with, it is just the nature of the beast. I would draw on an analogy from my flying days to explain why this is so. Imagine the cockpit of a WW I fighter aircraft. You probably have half a dozen or less simple dials and gauges, and a stick and throttle. Imagine trying to use that set of controls on an aircraft that can fly at high subsonic speeds at high altitude carrying hundreds of passengers for 12 hour transoceanic flights. Not going to work too well. This is basically where you were at with past technologies to build complex, distributed, heterogenous, connected enterprise systems. It could be done, but the end result was not going to be pretty and it was going to take you a long time to get there.

Now with WCF, it is more like climbing into the cockpit of a 777. There is a technological elegance to everything that is there. But there are still hundreds (if not thousands) of individual switches, controls, displays, electronic gages and dials, menu driven control panels, etc. A great deal of human engineering has gone into everything that is in there so that for any given common task, there are only a couple of relevant controls that you have to touch and put into place to get the job done. The challenge is in knowing which one of those hundreds of knobs and dials to tweak.

The same is true for WCF. Microsoft has created an incredibly powerful and technologically advanced platform that is well adapted to building large distributed enterprise systems. In order to do that, there needs to be hundreds of switches and knobs that you can throw to address different scenarios. The downside to that is bullet number three above - you have to learn which switches and knobs are relevant for a given task, and in what order to throw them.

This is somewhat aggravated right now in that we are only at Beta 1 of WinFx (and its parts WCF, WPF, and WinWF), and the names, shapes, and locations of all the knobs and switches is constantly changing as they work on that human engineering task of trying to make it easier to use. Meanwhile the documentation and samples are seriously lagging, so working with it right now is a little like stepping into that 777 cockpit without any labels on the controls. When you say to yourself, "I just need transactions and certificate based security", it is kind of like saying "I just need to call the flight attendant at the second aft flight station". Simple to describe, but God help you in figuring out which switches and knobs to throw. At least there are not really any destructive ones that you can throw by accident. If you get it wrong, your app may not work, but you would have to go out of your way to write some code that would do bad things when WCF fails to let you communicate.

I'm looking forward to continuing to work with this technology and learn what all those knobs and buttons are for. Learning all the controls of the aft cockpit of the F-14 to run the weapons system, navigation systems, communications systems, and other tasks was one of the funnest things I have done in my life. The fact that we got to do that while strapped to a couple of 50K lb + of thrust zorching through the sky pulling G's and landing on the carrier certainly helped make it interesting. Sitting at a computer leaves a little to be desired in that department, but the learning challenge is still just as fun.

I'll be speaking at Visual Studio Connections (part of DevConnections) in Las Vegas from 5-8 November. This is a great and growing conference that happens twice annually in the US, usually Orlando in the spring and Las Vegas in the fall, that I have been privileged to speak at for the last couple years. If you haven't been to one yet, you ought to be hammering your boss for permisson/funding to attend for the following reasons:

• It will rapidly and time-effectively expose you to new solution technologies you might not get a chance to explore on your own
• You will get concentrated advanced training in current and future technologies, getting you up to speed on them in far less time than you can achieve on your own
• You will get presentations from the top speakers in the business
• You will get a chance to network with peers in the industry, learn from others experiences employing .NET technologies, which will make you more effective at employing them yourself
• You will have a lot of fun (OK, maybe don't tell your boss this...)

You can learn a lot peripherally from the conference too by reading the DevConnections blog here. There are posts from other speakers as they develop their talks and their own observations and experiences at the conference.

I'll be presenting the following sessions:

VSM356: Build Custom Data Bound Business Objects and Collections
VSM351: Secure Smart Client ClickOnce Deployments
VID306: Build Event-Driven Applications with Indigo
VID309: Connect Smart Client Applications with Indigo

If you make it to the show (and you should!!), stop by and say hi!