Xamarin.Android automatically regenerates the /Resources/Resource.Designer.cs file every time the app is compiled, but because this file is included in version control, it's possible that it can be marked as read-only when TFS attempts to run a build. As a result, a build might fail.

Note: this is not a concern Team Foundation Server 2013 and 2015, which automatically check out files that are modified during a build. For earlier versions of TFS it is necessary to add a pre-build event to explicitly check out Resource.Designer.cs and remove the read-only flag so the build can progress:

1. In Visual Studio, right click on the TaskyAndroid project in Solution Explorer, select Properties, and click the Build Events tab.

   

2. Click the Edit Pre-build… button, enter the following snippet, and press OK:

   $(DevEnvDir)tf -checkout $(ProjectDir)Resources\Resource.Designer.cs
   attrib -r $(ProjectDir)Resources\Resource.Designer.cs

3. The project properties should now look like the following:

   

4. Save the TaskyAndroid project to complete the modification.