SetCursorPos Not Working

Question

I'm using the following library: http://www.codeproject.com/Articles/28064/Global-Mouse-and-Keyboard-Library?fid=1518257&df=90&mpp=25&noise=3&prof=False&sort=Position&view=Quick&fr=51#xx0xx

To help me work with low level mouse hooks in Windows 7. I create a timer to check the last time a mouse move event was fired, and if it's longer than a given time, I move the mouse to the top left corner of the screen using SetCursorPos(0,0)

Before moving the mouse, I took it's old coordinates, and saved them. So that when I receive the next MouseMove event I can replace the mouse in it's original location. However, upon called SetCursorPos(oldPos.x, oldPos.y), the mouse does not move.

I'm sure that the oldPos values are correct, however the cursor refuses to move. Could this be due to the library I'm using? Please help.

[DllImport("user32.dll", SetLastError = true)]
    public static extern bool SetCursorPos(int X, int Y);
        [DllImport("user32.dll")]
    public static extern bool GetCursorPos(out POINT lpPoint);
void mouseHook_MouseMove(object sender, MouseEventArgs e)
    {
        //If the mouse was not visible, move it back to it's original position
        if (!mouseVisible)
        {
            mouseVisible = true;

            SetCursorPos(cursorPosition.x, cursorPosition.y);
        }

        //Update the last moved time.
        lastMoved = DateTime.Now;
    }

private void hideMouse(object sender, EventArgs e)
    {
        if (mouseVisible && (DateTime.Now - lastMoved) > new TimeSpan(0, 0, 0, mouseControl.timeTrackBar.Value))
        {
            log.Debug("Hiding mouse.");

            //Store the current mouse position.
            GetCursorPos(out cursorPosition);

            //Hide the mouse.
            SetCursorPos(0, 0);
            log.Debug("Moving cursor to 0,0");

            mouseVisible = false;
        }

Answer 1

My guess is that this is what happens:

1. You move the mouse to 0,0 with SetCursor.
2. That act of calling SetCursor generates a mouse move event from your hook.
3. You respond to the mouse move by showing the cursor again and putting it back where it was before.