TeamBuild ClickOnce – Auto Incrementing Your Version Information

Using AssemblyInfoTask within your TFSBuild.proj file, you can set your builds to automatically increment your AssemblyVersion and AssemblyFileVersion.  You can also keep your application’s Publish Version in sync, which is useful if you’re publishing your application via ClickOnce. 

The Publish Version is important because that’s what ClickOnce looks at to see if there’s a new version available when the user runs the application.  Updating the AssemblyVersion or AssemblyFileVersion doesn’t tell ClickOnce that there’s a new version of your application to download.

There are a ton of blog posts like this one that tell you how to check in/out files from your TFS so I won’t repeat those steps.  The actual version updates happen inside the <AssemblyInfo> task:

<Project>
    <Import Project="$(MSBuildExtensionsPath)\Microsoft\AssemblyInfoTask\Microsoft.VersionNumber.Targets" />
    ...
    <Target Name="AfterGet">
        <Message Text="In After Get"/>

        <CreateItem Include="$(SolutionRoot)\My Project\AssemblyInfo.vb">
            <Output ItemName="AssemblyInfoFiles" TaskParameter="Include"/>
        </CreateItem>

        <Exec WorkingDirectory="$(SolutionRoot)\My Project\"
            Command="$(TF) checkout AssemblyInfo.vb" />

        <AssemblyInfo AssemblyInfoFiles="@(AssemblyInfoFiles)"
            AssemblyRevisionType="AutoIncrement"
            AssemblyRevisionFormat="0"
            AssemblyFileRevisionType="AutoIncrement"
            AssemblyFileRevisionFormat="0">

          <Output ItemName="MaxAssemblyVersion" TaskParameter="MaxAssemblyVersion" />
        </AssemblyInfo>
      </Target>
    ...
</Project>

For our project, we only want to update a specific AssemblyInfo.vb as opposed to recursively checking out all AssemblyInfo files to modify.  We used the <CreateItem> task to store the AssemblyInfo files into an array.  In our case it’s just one file (That’s why the <Exec> task looks a bit different than most examples out there on the web). 

Inside the <AssemblyInfo> task is pretty self-explanitory.  Setting the type and format of the Revision (you can do this to your Major, Minor, and Build as well) to AutoIncrement is what does the trick.  You don’t have to have an <Output> element, but I wanted to keep our Publish Version and Assembly Version in sync. 

We can use the variable @(MaxAssemblyVersion), which stems from the ItemName attribute, to hold our new Assembly Version.  I’ve previously posted about modifying the vbproj file to update the Publish Version so I won’t go into the details, but finding and replacing the needed element isn’t difficult.  Lastly you’ll want to check in your new AssemblyInfo file so that the next build increments your versions.