How to detect Help button press in Windows Forms MessageBox?

Question

I have a message box with 3 buttons: Yes, No, Help:

var result = MessageBox.Show("text", "title",
                MessageBoxButtons.YesNo,
                MessageBoxIcon.Warning,
                MessageBoxDefaultButton.Button1,
                true);

I can detect if Yes/No buttons where clicked something like this:

if(result == DialogResult.Yes)
    // some actions

How I can detect that Help button was pressed and execute my own code?

Answer 1

You want to handle the Form's HelpRequested event. See the example in the help topic at http://msdn.microsoft.com/en-us/library/szwxe9we.aspx.

public static DialogResult Show(
    string text,
    string caption,
    MessageBoxButtons buttons,
    MessageBoxIcon icon,
    MessageBoxDefaultButton defaultButton,
    MessageBoxOptions options,
    bool displayHelpButton
)

Answer 2

Except that doesn't work - not for me, anyway. I handle the underlying Form's HelpRequested event like the article says, and the event never gets called.