How to Disable Alt + F4 closing form?

Question

What is the best way to disable Alt + F4 in a c# win form to prevent the user from closing the form?

I am using a form as a popup dialog to dis

Answer 1

I believe this is the right way to do it:

protected override void OnFormClosing(FormClosingEventArgs e)
{
  switch (e.CloseReason)
  {
    case CloseReason.UserClosing:
      e.Cancel = true;
      break;
  }

  base.OnFormClosing(e);
}