title: My small FolderBrowserDialog implementation does not work
body: <p>I know there are a lot of FolderBrowserDialog implementations for WPF available.
  But my idea was writing a facade for OpenFileDialog and set the FOS_PICKFOLDERS flag, instead of writing a complete new implementation.</p>
  
  <p>But it does not work.</p>
  
  <pre><code>public sealed class FolderDialog 
  {
      private OpenFileDialog dlg;
  
      public FolderDialog()
      {
          this.dlg = new OpenFileDialog();
          SetOption(0x00000020, true);    // FOS_PICKFOLDERS  
          bool b = GetOption(0x00000020);
      }
  
      private bool GetOption(int option)
      {
          return (bool)typeof(FileDialog).InvokeMember("GetOption", BindingFlags.InvokeMethod | BindingFlags.NonPublic | BindingFlags.Instance, null, this.dlg, new object[] { option });
      }
  
      private void SetOption(int option, bool value)
      {
          typeof(FileDialog).InvokeMember("SetOption", BindingFlags.InvokeMethod | BindingFlags.NonPublic | BindingFlags.Instance, null, this.dlg, new object[] { option, value });
      }
  
      public string Title
      {
          get { return this.dlg.Title; }
          set { this.dlg.Title = value; }
      }
  
      public string FileName 
      {
          get { return this.dlg.FileName; }
      }
  
      public bool? ShowDialog()
      {
          return this.dlg.ShowDialog();
      }
  
      public bool? ShowDialog(Window owner)
      {
          return this.dlg.ShowDialog(owner);
      }
  }
  </code></pre>