SendMessage for keystroke is not working

Question

 

Hi all

 

could you please tell me why this code does not work? It should simulate the pression of TAB and then arrow DOWN, but nothing happens. I´m sure I have the right handle to the window, because I can click with the mouse on some of its buttons.

 

SetForegroundWindow(hwndWindow);

SetActiveWindow(hwndWindow);

SetFocus(hwndWindow);

SendMessage(hwndWindow, WM_SETFOCUS, VK_TAB, 0);  //tried also without

SendMessage(hwndWindow, WM_SETFOCUS, VK_TAB, 0);  //these 2 messages

Sleep(500);

SendMessage(hwndWindow, WM_KEYDOWN, VK_TAB, 0);

SendMessage(hwndWindow, WM_KEYUP, VK_TAB, 0);

Sleep(1000);

SendMessage(hwndWindow, WM_KEYDOWN, VK_DOWN, 0);

SendMessage(hwndWindow, WM_KEYUP, VK_DOWN, 0);

 

 

Many thanks in advance

 

Fede

Answer 1

No idea.  SendInput() is another mouse trap.

Answer 2

Thanks for reply, nobugz.

 

I tried with SendInput. It works (not on Vista). But since my application runs as a service,  SendInput requires that the service uses Local System Account. This causes conflict with other functionalities, so that´s why I need to use SendMessage or PostMessage.

 

Can someone else help, please?

Thanks in advance

 

 

Answer 3

Hello,
Please excuse me for being a little off topic:

For two days I have been suffering, I cannot understand:

I'm trying to emulate a button click on the Window 10 calculator. Since there are no real buttons of the "Button class" in the calculator, then:
I look through spy ++ which messages are sent to the calculator window when I click, for example, on the number 8:

000201C6 S WM_PARENTNOTIFY fwEvent:WM_LBUTTONDOWN xPos:191 yPos:493

I am sending the same message to the Calculator window:

HWND calculator_HWND = FindWindowW(NULL, L"Calculator"); //Get HWND calculator


WPARAM my_wparam;


 wchar_t* wchar_wparam = (wchar_t*)&my_wparam;
 wchar_wparam[0] = WM_LBUTTONDOWN;  // LOWORD-left click
 wchar_wparam[1] = 0;   //HIWORD(wParam) is undefined.                                           
LPARAM my_lparam; //Coordinate click

 wchar_t* wchar_laparam = (wchar_t*)&my_lparam;
 wchar_laparam[0] = 191;            //X                                         
 wchar_laparam[1] = 493;            //Y                                      
SendMessage(calculator_HWND, WM_PARENTNOTIFY, my_wparam, my_lparam);

After completing the SendMessage, I see a message in the calculator window in SPY ++:

000201C6 S WM_PARENTNOTIFY fwEvent:WM_LBUTTONDOWN xPos:191 yPos:493

But the number 8 is not pressed. The calculator does not respond to this message in any way. :(((

Please tell me what am I doing wrong?

Answer 4

Maybe you've forgotten to send WM_LBUTTONUP