Giving a MDI window a background image/tile (Views: 29)
Problem/Question/Abstract: How do I give my MDI window a background image or tile? Answer: This is a handy trick I found somewhere: Put an image called Image1 on your main form. Add the following routine to your main form: Make sure you have the following variables in your main form object: FClientInstance: TFarProc; FPrevClientProc: TFarProc; { MDI Background code } procedure TMainForm.ClientWndProc(var Message: TMessage); var Dc: hDC; Row: Integer; Col: Integer; begin with Message do case Msg of WM_ERASEBKGND: begin Dc := TWMEraseBkGnd(Message).Dc; // Tile Image on DC for Row := 0 to ClientHeight div Image1.Picture.Height do for Col := 0 to ClientWidth div Image1.Picture.Width do BitBlt(Dc, Col * Image1.Picture.Width, Row * Image1.Picture.Height, Image1.Picture.Width, Image1.Picture.Height, Image1.Picture.Bitmap.Canvas.Handle, 0, 0, SRCCOPY); Result := 1; end; else // Pass on other msg's Result := CallWindowProc(FPrevClientProc, ClientHandle, Msg, wParam, lParam); end; end; And put this in your mainform OnShow event: // MDI background tiles stuff, chain in de WndProc. FClientInstance := MakeObjectInstance(ClientWndProc); FPrevClientProc := Pointer(GetWindowLong(ClientHandle, GWL_WNDPROC)); SetWindowLong(ClientHandle, GWL_WNDPROC, LongInt(FClientInstance)); You now have a background! |