SendInput sending mouse input AND keyboard input

Question

=)

I am using C++ (not VC++) on windows7 laptop.

I have a problem with this method for moving the mouse x/y from it's current position. Every time it calls send input for a mouse event it moves the mouse but also turns off my screen (the equivalent of Fn+F2). I debugged the program and noticed that not only did mi but also ki and hi had values (this was for x=25, y=25 and absolure=false):

    mi:
      dx            25
      dy            25  
      mouseData     0   
      dwFlags       1   
      time          2686400 
      dwExtraInfo   0   
    ki:
      wVk           25  
      wScan         0
      dwFlags       25  
      time          0   
      dwExtraInfo   1   
    hi:
      uMsg          25
      wParamL       25  
      wParamH       0       

I have tried to set ki and hi to 0 but if I do that then mi is also set to 0 and then no mouse moves but the screen is still put to sleep! :$

Here are some of the methods I used.

int Controller::mouse_move(long x, long y, bool absolute) {
   mouse.dx = x;
   mouse.dy = y;

   if (absolute) {
       mouse.dwFlags = MOUSEEVENTF_MOVE | MOUSEEVENTF_ABSOLUTE;
   }else{
       mouse.dwFlags = MOUSEEVENTF_MOVE;
   }

   mouse.mouseData = 0;
   mouse.dwExtraInfo = 0;

   input.type = INPUT_MOUSE;
   input.mi = mouse;

   SendInput(1, &input, sizeof (input));

   return 0;
}

OR

int Controller::mouse_move(long x, long y, bool absolute, int index_vector_no) {
    input.type = INPUT_MOUSE;
    input.mi.dx = x;
    input.mi.dy = y;

    if (absolute) {
        input.mi.dwFlags = MOUSEEVENTF_MOVE | MOUSEEVENTF_ABSOLUTE;
    }else{
        input.mi.dwFlags = MOUSEEVENTF_MOVE;
    }

    input.mi.mouseData = 0;
    input.mi.dwExtraInfo = 0;

    input.ki.dwExtraInfo = 0;
    input.ki.dwFlags = 0;
    input.ki.time = 0;
    input.ki.wScan = 0;
    input.ki.wVk = 0;

    input.hi.uMsg = 0;
    input.hi.wParamH = 0;
    input.hi.wParamL = 0;

    SendInput(1, &input, sizeof (input));

    return 0;
}

Can anyone thing why this is sending keyboard input as well as mouse?! is it just something to do with my laptop configuration?

Thanks in advance! =)

Answer 1

The reason the others change is because they're all in a union, so they share the same memory.

About the screen turning off, you didn't set mi.time to 0, so it's uninitialized. It's often a good idea to start initializing these structs to {0}, so you don't forget things. The timestamp becomes some random number, which can cause a timeout on the display.

Answer 2

You can use this:

input.mi.time = 0;

Before:

input.mi.dwFlags = MOUSEEVENTF_MOVE | MOUSEEVENTF_ABSOLUTE | MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP;

It works for me.