Control.clientSize property
public Size clientSize [property getter]
public Size clientSize [property setter]
Gets the size of the control's client area or sets the control's bounds so that the client area is the requested size. The client area is the area of the control excluding its borders and caption.
The client area is always at position Point(0, 0); coordinates are usually relative to the client area.
Note that if you are changing the control's border you have to do so before setting the clientSize because changing the border can change the client area.
See also: Control, Size, clientRectangle, displayRectangle