gistfile1.cs

private const int DIALOG_LOGIN = 1;

protected override void OnCreate(Bundle savedInstanceState)
{
  base.OnCreate(savedInstanceState);
  this.SetContentView(R.Layouts.activity_android_dialog);
  
  var launchButton = FindViewById<Button>(R.Ids.btn_launch);
  launchButton.Click += delegate { ShowDialog(DIALOG_LOGIN); };
}