在項目中出現的問題：

     public class CheckComputerFreeState
     {
         /// <summary>
         /// 創建結構體用於返回捕獲時間
        /// </summary>
         [StructLayout(LayoutKind.Sequential)]
         struct LASTINPUTINFO
         {
             /// <summary>
             /// 設置結構體塊容量
            /// </summary>
             [MarshalAs(UnmanagedType.U4)]
             public int cbSize;

            /// <summary>
             /// 抓獲的時間
            /// </summary>
             [MarshalAs(UnmanagedType.U4)]
             public uint dwTime;
         }

        [DllImport("user32.dll")]
         private static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);
         /// <summary>
         /// 獲取鍵盤和鼠標沒有操作的時間
        /// </summary>
         /// <returns>用戶上次使用系統到現在的時間間隔，單位為秒</returns>
         public static long GetLastInputTime()
         {
             LASTINPUTINFO vLastInputInfo = new LASTINPUTINFO();
             vLastInputInfo.cbSize = Marshal.SizeOf(vLastInputInfo);
             if (!GetLastInputInfo(ref vLastInputInfo))
             {
                 return 0;
             }
             else
             {
                 var count = Environment.TickCount - (long)vLastInputInfo.dwTime;
                 var icount = count / 1000;
                 return icount;
             }
         }

    }

調用：

       static void Main(string[] args)
        {
            Timer t = null;
            t = new Timer((o) =>
           {
               var result = GetLastInputTime();
               Console.WriteLine(result);
               if (result < 1*60) return;
               if (t == null) return;
               t.Dispose();
               Console.WriteLine("電腦1分鍾未操作！");
           }, null, 1000, 1000);

            Console.ReadLine();
        }