Thread: Two simple questions.

  1. #1
    Registered User Queatrix's Avatar
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    Question Two simple questions.

    How can I send a message that makes the computer think the user pressed the left mouse button?

    Also, how can I send a message that makes the computer think the user pressed the 'A' key on the keyboard?

    Thanks, August.

  2. #2
    C++ Enthusiast jmd15's Avatar
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    Code:
    SendMessage(hwnd,WM_LBUTTONDOWN,MK_LBUTTON,MAKELPARAM(x,y));
    For some reason I don't think this is what you meant, but posted it in case it was.
    Trinity: "Neo... nobody has ever done this before."
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    To send click:
    SendMessage(handle_of_window, WM_LBUTTONDOWN, 0, 0);
    Sleep(50);
    SendMessage(handle_of_window, WM_LBUTTONUP, 0, 0);

    send a character, I think it's:
    SendMessage(handle_of_window, WM_CHAR, (WPARAM)'A', 0);

    I may be wrong on the last one, but anyway check msdn for SendMessage and WM_CHAR or WM_KEYDOWN/UP

  4. #4
    Registered User Queatrix's Avatar
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    I see. But this is not working. Why?

    Code:
    HWND hwndOnTop = GetFocus();
    SendMessage(hwndOnTop, WM_LBUTTONDOWN, 0, 0);

  5. #5
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    you can't just send a button down message. A click is a button down and button up. You also usually need to sleep for a few milliseconds between them for it to register correctly

  6. #6
    Registered User Queatrix's Avatar
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    I tried this:



    Sleep(3000);
    Beep(2000,100);
    HWND hwndOnTop = GetFocus();
    SendMessage(hwndOnTop, WM_LBUTTONDOWN, 0, 0);
    Sleep(100);
    SendMessage(hwndOnTop, WM_LBUTTONUP, 0, 0);


    It still does not work.

  7. #7
    Yes, my avatar is stolen anonytmouse's Avatar
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    Use the SendInput or mouse_event functions.

  8. #8
    C++ Enthusiast jmd15's Avatar
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    This should work as long as you get your desired window open in 3 seconds:
    Code:
    #include <windows.h>
    
    int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow)
    {
    HWND hwnd;
    Sleep(3000);
    hwnd=GetForegroundWindow();
    while(hwnd==NULL)
    {
    hwnd=GetForegroundWindow();
    }
    SendMessage(hwnd,WM_LBUTTONDOWN,(WPARAM)MK_LBUTTON,0);
    SendMessage(hwnd,WM_LBUTTONUP,0,0);
    return 0;
    }
    The problem was GetFocus() wasn't returning a handle. I tried GetFocus and it returned NULL so I used GetForegroundWindow(). Hope that helps. Oh not ALL programs need a time lapse to respond to those two messages, but I don't doubt that some do. So if no luck with the above code, try a little time lapse between messages.
    Trinity: "Neo... nobody has ever done this before."
    Neo: "That's why it's going to work."
    c9915ec6c1f3b876ddf38514adbb94f0

  9. #9
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    also, just sending an lbutton down/up to a window isn't going to do anything. The GetForegroundWindow function may return the top most window, but it won't return a handle to a button on the window. If you want a specific button, use FindWindow() then GetWindow with GW_CHILD and GW_HWNDNEXT until you find that button. Also Spy++ is your friend here.

  10. #10
    Registered User Queatrix's Avatar
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    Still, even if I can capture a child window's handle, how am I suppose to know if that is the one that is focused?

  11. #11
    C++ Enthusiast jmd15's Avatar
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    Well if it's not the focused window then make it the focused window, with SetFocus(HWND);.
    Trinity: "Neo... nobody has ever done this before."
    Neo: "That's why it's going to work."
    c9915ec6c1f3b876ddf38514adbb94f0

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