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Winfrom Panel Scroll End 的实现

场景：在一个panel里面有非常多的自定义绘制的控件，在拖拉滚动条的时候，控件的画面上有残影

不知道大家遇到过这种情况没，一直做web的winform经验太少，有更好的解决办法请贡献

首先放出我的解决思路：需要再滚动停止的时候重绘一下控件，panel的所有事件都加了一个打印输出，发现，滚动条在滚动的时候只有一个Scrol事件，是在滚动时候产生的，问题在于轻轻拖动滚动条，就会一瞬间产生N个Scrol，如果直接这个事件里面放重绘代码，太消耗资源，第二这个滚动条除了滚动事件，别的事件都没有，比如鼠标moseup mosedown等

实在没有办法，写了一个类变现的实现滚动停止的时候执行自己的方法，代码如下，写的不好，抛砖引玉，希望能有更好的解决方式

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
 
namespace Controller
{
    public delegate void VoidNotify();
    /// <summary>
    /// 滚动停止事件
    /// </summary>
    public class ScrollEnd
    {
        private static ScrollEnd instance;
        private static object Lock = new object();
        /// <summary>
        /// 滚动条事件计数
        /// </summary>
        private static int count = 0;
        /// <summary>
        /// Thread Loop 计数器
        /// </summary>
        private static int count2 = 0;
 
        /// <summary>
        /// 通知自定义事件
        /// </summary>
        public static VoidNotify Notify { get; set; }
 
        private Thread thread = null;
 
        private ScrollEnd()
        {
 
        }
        public static ScrollEnd GetInstance()
        {
            if (instance == null)
            {
                lock (Lock)
                {
                    if (instance == null)
                    {
                        instance = new ScrollEnd();
                    }
                }
            }
            return instance;
        }
 
        /// <summary>
        /// 滚动条事件触发ADD
        /// </summary>
        public void Add()
        {
            lock (Lock)
            {
                if (count2 == 0)
                {
                    thread = new Thread(new ThreadStart(Run));
                    thread.IsBackground = true;
                    thread.Start();
                }
                else
                {
                    count++;
                }
            }
        }
 
        /// <summary>
        /// 通过thread的间隔计数跟滚动事件的计数对比，判断滚动结束，然后执行自定义事件
        /// </summary>
        private void Run()
        {
            while (true)
            {
                if (count2 > count)
                {
                    break;
                }
                count2++;
                Thread.Sleep(30);
            }
            if (Notify!=null)
            {
                Notify();
            }
            count = 0;
            count2 = 0;
            thread = null;
            return;
        }
    }
}