procedure TForm1.ClientWndProc(var Message:TMessage);
var
MyDC:hDC;
Ro,Co:Word;
begin
with Message do
case Msg of
WM_ERASEBKGND:
begin
MyDC:=TWMEraseBkGnd(Message).DC;
for Ro:=0 to ClientHeight div Image1.Picture.Height do
for Co:=0 to ClientWidth div Image1.Picture.Width do
BitBlt(MyDC,Co*Image1.Picture.Width,Ro*Image1.Picture.Height,Image1.Picture.Width,Image1.Picture.Height,Image1.Picture.Bitmap.Canvas.Handle,0,0,SRCCOPY);
Result:=1;
end;
else
Result:=CallWindowProc(FPrevClientProc,ClientHandle,Msg,wParam,lParam);
end;
end;
然后在CREATE时间里面引用:
procedure TForm1.FormCreate(Sender: TObject);
begin
FClientInstance:=MakeObjectInstance(ClientWndProc);
FPrevClientProc:=Pointer(GetWindowLong(ClientHandle,GWL_WNDPROC));
SetWindowLong(ClientHandle,GWL_WNDPROC,LongInt(FClientInstance));
end;