If the user presses Ctrl-C while the MessageBox has focus, the message, MessageBox signature and MessageBoxButtons are copied to the clipboard.
I googled your headline and found this .
Or, if you really need a button with a copy, you can create your own MessageBox with a new window shape, and then do what you want with the buttons. Open it to save the MessageBox :
var myMessageBox = new CustomMessageBox(); myMessageBox.ShowDialog();
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