title: C# DLL Message Box
body: <p>Is it possible to have a C# DLL open a message box? Like in a WinForm:</p>
  
  <pre><code>MessageBox.Show("Message");
  </code></pre>
  
  <p>I relise that DLL's can't be executed directly but what if it were to be injected into a process to be run, then it could show the message box (if it's possible).</p>