private bool isPressed;
        public static long time;
        public static long timePassed;
        private void button2_Click(object sender, EventArgs e)
        {
            if (isPressed)
            {
                time = Environment.TickCount - timePassed;
                timePassed = Environment.TickCount;
            }
            else
            {
                isPressed = true;
                time = 0;
                timePassed = Environment.TickCount;
            }
            MessageBox.Show("距离上一次单击该按钮时隔：" + time.ToString() + "毫秒");
        }