In an ASP.NET project, in the aspx markup you can add a (non existent) method name to an event then use the Quick Fix to add the method hander.

If the target event is declared using the generic EventHandler<> type:

public class MyEventArgs : EventArgs {}
public event EventHandler<MyEventArgs> Foo;

Then the resulting signature for the generated event handler method contains an event type of TEventArgs instead of the actual target type (in this case MyEventArgs):

protected void OnMyFoo(object sender, TEventArgs e)
{
  throw new NotImplementedException();
}

Issue was closed