See Also: Button Members
A System.Windows.Forms.Button can be clicked by using the mouse, ENTER key, or SPACEBAR if the button has focus.
Set the Form.AcceptButton or Form.CancelButton property of a System.Windows.Forms.Form to allow users to click a button by pressing the ENTER or ESC keys even if the button does not have focus. This gives the form the behavior of a dialog box.
When you display a form using the Form.ShowDialog method, you can use the Button.DialogResult property of a button to specify the return value of Form.ShowDialog.
You can change the button's appearance. For example, to make it appear flat for a Web look, set the ButtonBase.FlatStyle property to FlatStyle.Flat. The ButtonBase.FlatStyle property can also be set to FlatStyle.Popup, which appears flat until the mouse pointer passes over the button; then the button takes on the standard Windows button appearance.
If the control that has focus accepts and processes the ENTER key press, the System.Windows.Forms.Button does not process it. For example, if a multiline System.Windows.Forms.TextBox or another button has focus, that control processes the ENTER key press instead of the accept button.