property Button.Focusable as Boolean
Gets or sets a value that indicates whether the control can receive focus.

TypeDescription
Boolean Gets or sets a value that indicates whether the control can receive focus.
By default, the Focusable property is True. In other words, the control receives the focus once the user clicks the control. Use the Focusable property to prevent receiving the focus, when user clicks the button. You can use this property to simulate buttons in a toolbar control. The Focusable property does not specify whether the control gains or loses the focus ( changing the focus ). This property has no effect if the user navigate the controls in the form using the keyboard. The control gains the focus using the keyboard ( TAB or SHIFT+TAB)  if the TabStop property of the control is True ( by default ). In conclusion, set the Focusable and TabStop property on False, to prevent receiving the focus using the mouse and the keyboard.