Mega Code Archive
Giving a MDI window a background imagetile
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Title: Giving a MDI window a background image/tile.
Question: 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!
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