Try to call

Application.ProcessMessages();
after disable a popup menu.

Andrey.

On 07.02.2021 17:09, Bo Berglund via lazarus wrote:
On Sun, 7 Feb 2021 14:01:46 +0000, Denis Kozlov via lazarus
<lazarus@lists.lazarus-ide.org> wrote:


I had a similar experience with taking a screenshot programmatically.
Simply waiting or processing application messages after hiding the form
often doesn't help, and results in a form being a part of the screenshot
anyway.

I managed to work around it by forcing Windows to repaint everything on
the desktop by broadcasting WM_PAINT message, like so:

SendMessageTimeout(HWND_BROADCAST, WM_PAINT, 0, 0, SMTO_ABORTIFHUNG,
1000, MsgResult);

You might also need to disable transition effects (fade-in and fade-out)
by setting the DWMWA_TRANSITIONS_FORCEDISABLED flag on the form before
hiding it, and then unsetting it when showing the form again.

DwmSetWindowAttribute(AForm.Handle, DWMWA_TRANSITIONS_FORCEDISABLED,
@dwAttribute, SizeOf(dwAttribute));

Good luck,
Denis

Thanks for the suggestion!

It turned out that (from a suggestion on the Lazarus forum) I could use a
sleep(300) right before the call to the CopyScreenRect() instead of the other
failed tests.

Apparently the menu item is subject to Windows "animation" when it is closed...

So this is now the code and it does work:

procedure TfrmMain.miCopyImageClick(Sender : TObject);
begin
   Sleep(300);
   CopyScreenRect;
end;

procedure TfrmMain.CopyScreenRect;
var
   MyCapture : TBgraBitmap;
   Clip: TRect;
begin
   try
     Clip := Bounds(Self.Left, Self.Top, Self.Width, Self.Height);
     Self.Visible := false; //To remove the capture frame from image
     MyCapture := TBgraBitmap.Create();
     try
       MyCapture.TakeScreenShot(Clip);
       Self.Visible := true;
       Clipboard.Assign(MyCapture.Bitmap);
     finally
       MyCapture.Free;
     end;
   except
     on E: exception do
       Clipboard.AsText := E.Message;
   end;
end;

I tried various values for the sleep time and settled for 300, 200 does not
quite fix it - a faded shadow image still remains.




--
Andrey
--
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