Exit Methods in C# Application

Environment.Exit() method

The Environment.Exit() method terminates the process and returns an exit code to the operating system −

Environment.Exit(exitCode);

Use exitCode as 0 (zero) to show that the process completed successfully.

Use exitCode as a non-zero number to show an error, for example −

Environment.Exit(1) − Return a value 1 to show that the file you want is not present
Environment.Exit(2) − Return a value 2 to indicate that the file is in an incorrect format.

To close a subapplication or current thread in a Windows Form, use theSystem.Windows.Forms.Application.ExitThread( ).

private void buttonClose_Click(object sender, EventArgs eventArgs) {
   System.Windows.Forms.Application.ExitThread( );
}