判断电脑长时间未使用锁屏

using System.Runtime.InteropServices;

        private void timer1_Tick(object sender, EventArgs e)
        {
            //判断空闲时间是否超过1分钟,超过则自动关闭窗口
            if (GetIdleTick() / 1000 >= 1 * 60)
            {
                Application.Exit();
                this.Close();
            }
        }

        /// <summary>
        /// 获取鼠标键盘空闲时间
        /// </summary>
        /// <returns></returns>
        public static long GetIdleTick()
        {
            LASTINPUTINFO lastInputInfo = new LASTINPUTINFO();
            lastInputInfo.cbSize = Marshal.SizeOf(lastInputInfo);
            if (!GetLastInputInfo(ref　lastInputInfo)) return 0;
            return Environment.TickCount - (long)lastInputInfo.dwTime;
        }
        private struct LASTINPUTINFO
        {
            [MarshalAs(UnmanagedType.U4)]
            public int cbSize;
            [MarshalAs(UnmanagedType.U4)]
            public uint dwTime;
        }
        /// <summary>
        /// 调用windows API获取鼠标键盘空闲时间
        /// </summary>
        /// <param name="plii"></param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);