WPF 检测输入状态

        [DllImport("user32.dll")]
        static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

        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;
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct LASTINPUTINFO
        {
            [MarshalAs(UnmanagedType.U4)]
            public int cbSize;
            [MarshalAs(UnmanagedType.U4)]
            public uint dwTime;
        }