Question

I want to be able to use the space key to modify the behavior of the mouse while it is held down. Without knowing better I am imagining it involves some kind of coordination between two (or three) event handler – mousemove, keydown, and keyup. But I am wondering if there is some way to handle it entirely within one event handler – mousemove.

Example code to give an idea of what I hope to be able to do…

        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (Keyboard.KeyDown == Keys.Space)
                {
                    /* Do modified behavour for left mouse being held down while 
                    space is also held down */
                }
                else
                {
                    // Do normal behavour for left mouse being held down
                }

            }
        }

Is something like this possible or will I have to save the state of the space key to a class variable using keydown event handler and check it with the mouse move handler?

Answer 1

You should set a variable in your KeyDown-Event and check it in your MouseEvent:

bool buttonpressed = false;
private void KeyDown_Event(object s, System.Windows.Forms.KeyEventArgs e)
{
   if(e.KeyCode == KeyCode.Space)
      buttonpressed = true;
   else
      buttonpressed = false;
}

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (buttonPressed)
                {
                    /* Do modified behavour for left mouse being held down while 
                    space is also held down */
                }
                else
                {
                    // Do normal behavour for left mouse being held down
                }

            }
        }