Key Presses and Mouse Clicks

[Anonymous]

How can I simulate key presses and mouse clicks through code?
I'm using Visual C++ and I'm making a Win32 application
NOT (!) using MFC.


I know of the SendInput(.......) function that is supposed to do this.

However, when I add it to my code and compile I get an error saying SendInput() is an unknown function although I included the header file for this function that was specified in the MSDN documentation.

Is there another function I can use to do this or can anyone get the SendInput function to work?

Last option - if anyone knows how to do this using MFC and no other way, please tell me.

[Quantrizi]

This will probably work:

case WM_KEYRIGHT:
//do whatever it's supposed to do
break;

This is when the right arrow key is pressed. This goes in the message thing switch (nMsg). There are others to. Here's the mouse one:

case WM_LEFTBUTTONDOWN:
//do whatever it's supposed to do
break;

That goes in the same place. This is when the left mouse button is clicked.

[Guardian]

Have you considered the SendMessage function.
It allows you to send a messages to your own meessage queue like this;

        case WM_CHAR: 
            switch (wParam) 
            { 
                case 0x08:          // Backspace 
                // Move the caret back one space, and then 
                // process this like the DEL key. 
 
                    if (nCaretPosX > 0) 
                    { 
                        nCaretPosX--; 
                        SendMessage(hwnd, WM_KEYDOWN, 
                            VK_DELETE, 1L); 
                    } 
                    break; 
 
                case 0x09:          // Tab 
                // Tab stops exist every four spaces, so add 
                // spaces until the user hits the next tab. 
 
                    do 
                    { 
                        SendMessage(hwnd, WM_CHAR, ' ', 1L); 
                    } while (nCaretPosX % 4 != 0); 
                    break;

You get the idea.

Here's the info on it.

LRESULT SendMessage(
  HWND hWnd,      // handle to destination window
  UINT Msg,       // message
  WPARAM wParam,  // first message parameter
  LPARAM lParam   // second message parameter
);

Parameters
hWnd
[in] Handle to the window whose window procedure will receive the message. If this parameter is HWND_BROADCAST, the message is sent to all top-level windows in the system, including disabled or invisible unowned windows, overlapped windows, and pop-up windows; but the message is not sent to child windows.

Msg
[in] Specifies the message to be sent.

wParam
[in] Specifies additional message-specific information.

lParam
[in] Specifies additional message-specific information.


Return Values
The return value specifies the result of the message processing; it depends on the message sent.

[Ken Fitlike]

If you search the winuser.h header for the SendInput fn you will find it is defined within a #if (_WIN32_WINNT > 0x0400)....#endif block.

So try #defining _WIN32_WINNT 0x0401 prior to #include <windows.h> (or something more appropriate to your os version).
Although this should compile with no errors there is no guarantee the fn will work.

I'd be curious to find out if 'SendInput' does work - and what os you are compiling on. Might be a useful addition to the FAQ.