C#获取键盘和鼠标操作的时间的类

///

/// 创建结构体用于返回捕获时间
///

[StructLayout(LayoutKind.Sequential)]
struct LASTINPUTINFO
{
///

/// 设置结构体块容量
///

[MarshalAs(UnmanagedType.U4)]
public int cbSize;

        /// <summary>
        /// 抓获的时间
        /// </summary>
        [MarshalAs(UnmanagedType.U4)]
        public uint dwTime;
    }

    [DllImport("user32.dll")]
    private static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);
    /// <summary>
    /// 获取键盘和鼠标没有操作的时间
    /// </summary>
    /// <returns>用户上次使用系统到现在的时间间隔，单位为秒</returns>
    public static long GetLastInputTime()
    {
        LASTINPUTINFO vLastInputInfo = new LASTINPUTINFO();
        vLastInputInfo.cbSize = Marshal.SizeOf(vLastInputInfo);
        if (!GetLastInputInfo(ref vLastInputInfo))
        {
            return 0;
        }
        else
        {
            long count = Environment.TickCount - (long)vLastInputInfo.dwTime;
            //long icount = count / 1000;
            return count;
        }
    }

private void timer1_Tick(object sender, EventArgs e)
{
int sunNumber=int.Parse(GetLastInputTime().ToString());
if (sunNumber >= 30000)
{
this.Close();
}

    }