c# winform 如何得知用户是否正在操作电脑

Question

c# winform 如何得知用户是否正在操作电脑
就像QQ的那个离开状态，当用户离开电脑不操作时，QQ就会检测到用户已离开,这个功能用C#如何做
还有就是不要建议我用全局钩子，因为这样会比较耗资源

Answer 1

捕获键盘的OnKeyDown事件，捕获MouseMove事件

Answer 2

namespace ActivityMonitor
{
    using System;
    using System.Runtime.InteropServices;    class ActivityMonitor : System.ComponentModel.Component
    {
        public void Start() 
        {
            this.isIdle = false;
            timer.Elapsed -= Timer_Elapsed;
            timer.Elapsed += Timer_Elapsed;
            timer.Interval = this.resolution;
            timer.Start();
        }        public void Stop() 
        {
            timer.Stop();
        }        public bool IsIdle 
        {
            get { return this.isIdle; }
            private set
            {
                if (this.isIdle != value)
                {
                    this.isIdle = value;                    if (isIdle && OnIdle != null)
                    {
                        OnIdle(this, EventArgs.Empty);
                    }
                    if (!isIdle && OnActive != null)
                    {
                        OnActive(this, EventArgs.Empty);
                    }
                }
            }
        }        public int IdleTimeOut 
        { 
            get { return idleTimeOut; }
            set { idleTimeOut = Math.Max(50, value); }
        }        public int Resolution 
        { 
            get { return resolution; } 
            set { resolution = Math.Max(50, value); } 
        }        public event EventHandler OnIdle;
        public event EventHandler OnActive;        private void Timer_Elapsed(object sender, EventArgs e)
        {
            LASTINPUTINFO lastInputInfo = new LASTINPUTINFO();
            lastInputInfo.size = 8;            if (GetLastInputInfo(ref lastInputInfo))
            {
                lastActivity = Math.Max(lastActivity, lastInputInfo.lastTick);                int diff = Environment.TickCount - lastActivity;
                this.IsIdle = diff > this.IdleTimeOut;
            }
        }        private bool isIdle = false;
        private int idleTimeOut = 5000;
        private int resolution = 100;
        private int lastActivity = Environment.TickCount;
        private System.Timers.Timer timer = new System.Timers.Timer();        [StructLayout(LayoutKind.Sequential)]
        private struct LASTINPUTINFO
        {
            public int size;
            public int lastTick;
        }
        [DllImport("User32")]
        private static extern bool GetLastInputInfo(ref LASTINPUTINFO lii);
    }    class UnitTest
    {
        static void Main()
        {
            ActivityMonitor monitor = new ActivityMonitor();
            monitor.IdleTimeOut = 2000;                                     // 2 seconds
            monitor.OnIdle += delegate { Console.WriteLine("On idle"); };
            monitor.OnActive += delegate { Console.WriteLine("On active"); };            monitor.Start();
            Console.ReadLine();
        }
    }
}
It's my post on another thread. The monitor doesn't use hook but the GetLastInputInfo API.
我想使用c#做一个 检测键盘 鼠标 空闲状态的程序，请问有什么方法么？