Test if the Ctrl key is down using C#

Question

I have a form that the user can double click on with the mouse and it will do something. Now I want to be able to know if the user is also holding the Ctrl key do

Answer 1

Even this also

 private void Control_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        if (ModifierKeys == Keys.Control)
            MessageBox.Show("with CTRL");
    }