title: When does Visual Studio call target AfterBuild & BeforeBuild? And how is it handled when these targets are not defined?
body: <p>Today I meet a similar problem and it reminds me about this thread. In Visual Studio, if we open the .csproj file, we see that they tell us to uncomment the two targets AfterBuild and BeforeBuild so as to execute them after and before the build of the current project accordingly.</p>
  
  <p>My questions are: Where are these two targets called in Visual Studio? And how is it handled if the targets are not defined (be commented out) ? </p>