How to know user has clicked “X” or the “Close” button?

Question

In MSDN I found CloseReason.UserClosing to know that the user had decided to close the form but I guess it is the same for both clicking the X button or clickin

Answer 1

if (this.DialogResult == DialogResult.Cancel)
        {

        }
        else
        {
            switch (e.CloseReason)
            {
                case CloseReason.UserClosing:
                    e.Cancel = true;
                    break;
            }
        }

if condition will execute when user clicks 'X' or close button on form. The else can be used when user clicks Alt+f4 for any other purpose