Modales Form finden, auf welches die Anwendung gerade wartet

[DeddyH]

Delphi-Quellcode:

function GetModalWindow(SomeWindow: HWnd): HWnd;
var
  WindowList: TList;
  hThread: DWORD;

  function EnumFunc(aWnd: HWnd; List: lParam): Boolean; stdcall;
  begin
    if ((GetWindowLong(aWnd, GWL_EXSTYLE) and WS_EX_MDICHILD) = 0) and
       IsWindowEnabled(aWnd) and IsWindowVisible(aWnd) then
      TList(List).Add(Pointer(aWnd));
    Result := true;
  end;

begin
  Result := 0;
  if SomeWindow <> 0 then
    begin
      WindowList := TList.Create;
      try
        hThread := GetWindowThreadProcessID(SomeWindow);
        EnumThreadWindows(hThread, @EnumFunc, lParam(WindowList));
        if WindowList.Count = 1 then
          Result := HWnd(WindowList[0]);
      finally
        WindowList.Free;
      end;
    end;
end;

function IsThreadTopWindow(aWnd: HWnd): Boolean;
var
  NextWnd: HWnd;
  aThreadID, NextThreadID: DWORD;
begin
  Result := true;
  if aWnd <> 0 then
    begin
      aThreadID := GetWindowThreadProcessID(aWnd);
      NextWnd := GetWindow(aWnd, GW_HWNDPREV);
      while Result and (NextWnd <> 0) do
        begin
          NextThreadID := GetWindowThreadProcessID(NextWnd);
          if (NextThreadID = aThreadID) and IsWindowVisible(NextWnd) then
            Result := false
          else
            NextWnd := GetWindow(NextWnd, GW_HWNDPREV);
        end;
    end;
end;

function BringToForeground(aWnd: HWnd): Boolean;
const
  DRAWFLAGS = RDW_ERASE or RDW_INVALIDATE or RDW_UPDATENOW or RDW_ALLCHILDREN;
  MOVEFLAGS = SWP_NOMOVE or SWP_NOSIZE;
  SHOWMOVEFLAGS = MOVEFLAGS or SWP_SHOWWINDOW;
begin
  Result := true;
  if (aWnd <> 0) and IsWindowVisible(aWnd) then
    begin
      Result := SetWindowPos(aWnd, HWND_TOPMOST, 0, 0, 0, 0, MOVEFLAGS) and
                SetWindowPos(aWnd, HWND_NOTOPMOST, 0, 0, 0, 0, MOVEFLAGS) and
                SetWindowPos(aWnd, HWND_TOP, 0, 0, 0, 0, SHOWMOVEFLAGS);
      if Result then
        RedrawWindow(aWnd, nil, 0, DRAWFLAGS);
    end;
end;

Damit klappt das (bislang) auch bei fremden Anwendungen. Für die eigene wäre so etwas denkbar (Prozedur ist Applicaton.OnIdle zugewiesen):

Delphi-Quellcode:

procedure TFrmMain.DoOnIdle(Sender: TObject; var Done: Boolean);
var
  ModalWnd: HWnd;
begin
  ModalWnd := GetModalWindow(Handle);
  if (ModalWnd <> 0) and not IsThreadTopWindow(ModalWnd) then
    BringToForeground(ModalWnd);
  Done := true;
end;