VB Code:
Private Declare Function InvertRect Lib "user32" (ByVal hdc As Long, lpRect As Rect) As Long
Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetClientRect Lib "user32" (ByVal hwnd As Long, lpRect As Rect) As Long
Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Type Rect
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private rct As Rect
Private Sub Command1_Click()
GetClientRect GetDesktopWindow, rct
InvertRect GetWindowDC(GetDesktopWindow), rct
End Sub