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Why doesn't my cursor switch to hourglass in my FindDialog in Delphi?

I just open my FindDialog with

FindDialog.Execute;

In my FindDialog.OnFind event, I want to change the cursor to an hourglass to search large files, which may take a few seconds. So in the OnFind event, I do this:

Screen.Cursor := crHourglass;
(code that searches for the text and displays it) ...
Screen.Cursor := crDefault;

What happens when searching for text, the cursor correctly changes to an hourglass (or rotating circle in Vista), and then returns to the pointer when the search is completed.

However, this only happens in basic form. This does not happen in FindDialog itself. The default cursor remains in FindDialog during the search. While the search is in progress, if I move the cursor over FindDialog, it changes to the default value, and if I move it over the main form, it becomes an hourglass.

, . - - , ?

, Delphi 2009.

+5
2

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procedure TForm1.FindDialog1Find(Sender: TObject);
begin
  SetClassLong(TFindDialog(Sender).Handle, GCL_HCURSOR, Screen.Cursors[crHourGlass]);
  try
    Screen.Cursor := crHourglass;
    try
//    (code that searches for the text and displays it) ...
    finally
      Screen.Cursor := crDefault;
    end;
  finally
    SetClassLong(TFindDialog(Sender).Handle, GCL_HCURSOR, Screen.Cursors[crDefault]);
  end;
end;


FindDialog WM_SETCURSOR "SetCursor". , .

type
  TForm1 = class(TForm)
    FindDialog1: TFindDialog;
    ...
  private
    FSaveWndProc, FWndProc: Pointer;
    procedure FindDlgProc(var Message: TMessage);
    ...
  end;

....
procedure TForm1.FormCreate(Sender: TObject);
begin
  FWndProc := classes.MakeObjectInstance(FindDlgProc);
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  classes.FreeObjectInstance(FWndProc);
end;

procedure TForm1.FindDialog1Find(Sender: TObject);
begin
  FSaveWndProc := Pointer(SetWindowLong(FindDialog1.Handle, GWL_WNDPROC,
        Longint(FWndProc)));
  try
    Screen.Cursor := crHourGlass;
    try
//    (code that searches for the text and displays it) ...
    finally
      Screen.Cursor := crDefault;
    end;
  finally
    if Assigned(FWndProc) then
      SetWindowLong(FindDialog1.Handle, GWL_WNDPROC, Longint(FSaveWndProc));
//    SendMessage(FindDialog1.Handle, WM_SETCURSOR, FindDialog1.Handle,
//        MakeLong(HTNOWHERE, WM_MOUSEMOVE));
    SetCursor(Screen.Cursors[crDefault]);
  end;
end;

procedure TForm1.FindDlgProc(var Message: TMessage);
begin
  if Message.Msg = WM_SETCURSOR then begin
    SetCursor(Screen.Cursors[crHourGlass]);
    Message.Result := 1;
    Exit;
  end;
  Message.Result := CallWindowProc(FSaveWndProc, FindDialog1.Handle,
      Message.Msg, Message.WParam, Message.LParam);
end;
+3

Application.ProcessMessages; .

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