Is it possible to simulate mouse move and mouse clicks at hidden window?

Question

So is there a way to make my Win32 application "think" that the mouse is moving over its window and making some clicks when the actual window is hidden (i mean ShowWindow(hWnd, SW_HIDE);)?

I tried to simulate mouse moving with PostMessage and SendMessage but no luck so far.

int x = 0;
int y = 0;
while (true)
{
    SendMessage(hwnd, WM_MOUSEMOVE, 0, MAKELPARAM(x, y));
    x += 10;
    y += 10;
    Sleep(100);
}

Is this even possible?

It can be achieved, as far as i know, You must translate the coordinates to the hidden window ones, so the messagepump will assume, the click happened inside the hidden window. I hope this helps: http://support.microsoft.com/kb/11570 — icbytes, Jul 11 '14 at 15:53
Where does this code run? If its on the main UI thread then, no, that won't work. If it is to fool Windows to prevent the work station locking then, no, that won't work. — Hans Passant, Jul 11 '14 at 18:10

score 7 · Accepted Answer · answered Jul 13 '14 at 21:07

Yes it's possible. This is a test hidden window:

#define UNICODE
#include <Windows.h>
#include <Strsafe.h>
#include <Windowsx.h>

LRESULT CALLBACK WndProc(HWND Hwnd, UINT Msg, WPARAM WParam, LPARAM LParam);

INT CALLBACK
WinMain(HINSTANCE hInstance,
        HINSTANCE hPrevInstance,
        LPSTR lpCmdLine,
        INT nCmdShow)
{
  WNDCLASSEX WndClass;

  ZeroMemory(&WndClass, sizeof(WNDCLASSEX));

  WndClass.cbSize           = sizeof(WNDCLASSEX);
  WndClass.lpfnWndProc      = WndProc;
  WndClass.hInstance        = hInstance;
  WndClass.lpszClassName    = L"HiddenWinClass";

  if(RegisterClassEx(&WndClass))
  {
    HWND Hwnd;
    MSG Msg;

    Hwnd = CreateWindowEx(0, L"HiddenWinClass", L"Nan",
      0, 0, 0, 0, 0, NULL, NULL, hInstance, NULL);

    if(Hwnd)
    {
      UpdateWindow(Hwnd);
      ShowWindow(Hwnd, SW_HIDE);
      while(GetMessage(&Msg, 0, 0, 0) > 0)
      {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
      }
    }
  }

  return 0;
}


LRESULT CALLBACK
WndProc(HWND Hwnd,
        UINT Msg,
        WPARAM WParam,
        LPARAM LParam)
{
  TCHAR Message[255];

  switch(Msg)
  {
    case WM_MOUSEMOVE:
      StringCbPrintf(Message, sizeof(Message), L"(%d, %d)",
        GET_X_LPARAM(LParam), GET_Y_LPARAM(LParam));
      MessageBox(NULL, Message, L"WM_MOUSEMOVE", MB_OK);
      break;
    default:
      return DefWindowProc(Hwnd, Msg, WParam, LParam);
  }

  return 0;
}

and this is your code:

#define UNICODE
#include <Windows.h>

int
main(int argc, char **argv)
{
  HWND Hwnd;

  if((Hwnd = FindWindow(L"HiddenWinClass", L"Nan")))
  {
    int x, y;

    for(x = y = 0 ; ; x += 10, y += 10)
    {
      SendMessage(Hwnd, WM_MOUSEMOVE, 0, MAKELPARAM(x, y));
      Sleep(100);
    }
  }

  return 0;
}

It works nicely.

Is it possible to simulate mouse move and mouse clicks at hidden window?

1 Answers1