Snippit covering showing Rdp Remote App Window

// Some example code that may help you with activating an Rdp remote application
// Possibly incomplete as this is taken from a complete application but it hopefully will
// help. If you have any improvements to suggest, email [email protected]

// No copyright in the below code is claimed (though it is an original work based upon code from a number
// of different sources).

function FindRdpWindowHandleCallback(handle: THandle; lParam: LPARAM): Boolean; stdcall;

  function isMainWindow(handle: HWND): Boolean;
  begin
    result := (GetWindow(handle, GW_OWNER) = HWND(0)) and (IsWindowVisible(handle) or IsIconic(handle));
  end;

var
  handleData: PHandleData;
  processId: ULONG;
  hwClassName: Array[0..255] of Char;
begin
  if GetClassName(handle, hwClassName, SizeOf(hwClassName)) <> 0 then begin
    // TXxxYyyZzz is the class of a form created by the DLL, which manages communication
    // via the virtual channels.
    if (StrComp(hwClassName, 'TXxxYyyZzz') = 0) then
      // If we have an exact class name match, we have our window
      result := true
    else begin
      handleData := PHandleData(lParam);
      processId := 0;
      // If no exact match, try comparing process ids. If we have a match,
      // it is possibly the window we are looking for.
      GetWindowThreadProcessId(handle, &processId);
      if (handleData^.processId = processId) and isMainWindow(handle) then begin
        handleData^.bestHandle := handle;
        result := false;
      end else
        result := true
    end;
  end else
    result := true;
end;

function ForceForegroundWindow(lnHWND: HWND): Boolean;
var
  nForeThread: Cardinal;
  nAppThread: Cardinal;
begin
  nForeThread := GetWindowThreadProcessId(GetForegroundWindow(), NIL);
  nAppThread := GetCurrentThreadId();
  if nForeThread <> nAppThread then begin
    if AttachThreadInput(nForeThread, nAppThread, True) then begin
      if BringWindowToTop(lnHWND) then
        result := ShowWindow(lnHWND, 0)
      else
        result := False;
      AttachThreadInput(nForeThread, nAppThread, False);
    end else
      result := False;
  end else begin
    if BringWindowToTop(lnHWND) then
      result := ShowWindow(lnHWND, 0)
    else
      result := False;
  end;
end;

function TRdpChannel.GetRdpHandle: HWND;
begin
  // Usually we have the Rdp window handle becaause we create the process
  if IsWindow(FRdpHandle) then
    result := FRdpHandle
  else begin
    // If the locally maintained Rdp handle no longer refers to a window, attempt to
    // locate an open RDP manager window (created by the DLL)
    GetWindowThreadProcessId(FCallManager.Handle, FHandleData.processId);
    FHandleData.bestHandle := 0;
    EnumWindows(@FindRdpWindowHandleCallback, NativeInt(@FHandleData));
    FRdpHandle := FHandleData.bestHandle;
    result := FRdpHandle;
  end;
end;

procedure TRdpChannel.ShowApplication;
var
  h: HWND;
  hClassName: Array[0..255] of Char;
begin
  h := GetRdpHandle;
  SetStatus(5, 'Show application called');
  if IsWindow(h) then begin
    if GetClassName(h, hClassName, SizeOf(hClassName)) <> 0 then begin
      // Attempts to restore a Delphi app, which has a 0 pixel main window
      // and apparently documentation says that it should be restored by
      // sending a WM_SYSCOMMAND message with SC_RESTORE as a parameter. Does
      // not always appear to work if the user clicks the minimise button on the
      // app main window.
      if (StrComp(hClassName, 'TApplication') = 0) then
        PostMessage(h, WM_SYSCOMMAND, SC_RESTORE, 0);
    end;
    if ShowWindow(h, SW_RESTORE) then begin
      if not SetForegroundWindow(h) then
        ForceForegroundWindow(h);
    end if ShowWindow(h, SW_SHOWDEFAULT) then begin
      if not SetForegroundWindow(h) then
        ForceForegroundWindow(h);
    end else begin
      if ShowWindow(h, SW_MINIMIZE) then begin
        if not OpenIcon(h) then
          ForceForegroundWindow(h);
      end else
        ForceForegroundWindow(h);
    end;
  end;
end;