Winfrom 定时锁屏

 #region 锁屏

        public struct LASTINPUTINFO

        {

            [MarshalAs(UnmanagedType.U4)]

            public int cbSize;

            [MarshalAs(UnmanagedType.U4)]

            public uint dwTime;

        }

        [DllImport("user32.dll")]

        public static extern bool GetLastInputInfo(ref    LASTINPUTINFO plii);

        public long getIdleTick()

        {

            LASTINPUTINFO vLastInputInfo = new LASTINPUTINFO();

            vLastInputInfo.cbSize = Marshal.SizeOf(vLastInputInfo);

            if (!GetLastInputInfo(ref    vLastInputInfo)) return ;

            return Environment.TickCount - (long)vLastInputInfo.dwTime;

        }

        private void timer2_Tick(object sender, EventArgs e)

        {

            long i = getIdleTick() / ;

            if (i > )//(i > 10 * 1000)//超过一分钟

            {

                suoping();

            }

        }

        private void butsp_Click(object sender, EventArgs e)

        {

            suoping();

        }

        void suoping()

        {

            this.timer2.Enabled = false;

            frmpassword frm = new frmpassword();

            frm.ShowDialog();

            if (frm.DialogResult == DialogResult.OK)

                this.timer2.Enabled = true;

            else

                Application.ExitThread();

        }

        #endregion