Question

I mean exit to system tray, not minimize to system tray, ie when you click on the “red cross” in the top right corner on a Windows form, instead of application closing, it runs in the system tray instead.

Answer 1

You can hook to Form Closing event and cancel the closing event and hide the form

sample code

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            e.Cancel = true;
            this.Hide();
        }