本文共 6091 字，大约阅读时间需要 20 分钟。

一、后台处理：

public void ProcessRequest(HttpContext context)        {            //处理WebSocket 请求            context.AcceptWebSocketRequest(DoWork);        }        /// 
        /// 委托处理函数定义        /// 
        /// 当前WebSocket上下文        /// 
           public async Task DoWork(AspNetWebSocketContext context)        {            //1.获取当前WebSocket 对象            WebSocket socket = context.WebSocket;            string filename = "";            //2.监视相应            while (true)            {                /*                 * 此处缓存数组指定读取客户端数据的长度                 * 如果客户端发送数据超过当前缓存区，则会读取多次                 */                ArraySegment
   
     buffer = new ArraySegment
    
     (new byte[1024 * 256]);                //接收客户端信息                CancellationToken token;                WebSocketReceiveResult result = await socket.ReceiveAsync(buffer, token);                if (socket.State == WebSocketState.Open)                {                    //判断是否已经到了最后                    int curLength = Math.Min(buffer.Array.Length, result.Count);                    //判断用户传入的类型进行处理                    if (result.MessageType == WebSocketMessageType.Text)                    {                        string msg = Encoding.UTF8.GetString(buffer.Array, 0, curLength);                        filename = msg;                        buffer = new ArraySegment
     
      (Encoding.UTF8.GetBytes("接收文件名成功:" + filename));                        await socket.SendAsync(buffer, WebSocketMessageType.Text, true, CancellationToken.None);                    }                    else if (result.MessageType == WebSocketMessageType.Binary)                    {                        //创建并保存文件,如果上传成功，返回当前接收到的文件大小                        string msg = SaveFile(filename, buffer, curLength);                        buffer = new ArraySegment
      
       (Encoding.UTF8.GetBytes(curLength.ToString()));                        await socket.SendAsync(buffer, WebSocketMessageType.Text, true, CancellationToken.None);                    }                }                else { break; }            }        }        /// 
       
        /// 追加二进制数据到文件        /// 
        public string SaveFile(string file, ArraySegment
       
         buffer, int Length)        {            //去除文件名中的前后空格            file = file.Trim();            string fullname = @"F:\JavaScript_Solution\H5Solition\UploadWebForm\content\" + file;            try            {                FileStream fs = new FileStream(fullname, FileMode.Append, FileAccess.Write);                try                {                    byte[] result = buffer.ToArray();                    fs.Write(result, 0, Length);                }                finally                {                    fs.Close();                }                return "保存文件成功";            }            catch (Exception ex)            {                return ex.Message;            }        }
       
      
     
    
   

HTML：

   
    
    
        
     
      分段读取文件：
     
        
     
            
      
      
            
      ∅            
                  
                  
      
        
     
    
    
   

/*    * 测试WebSocket上传    * 本地浏览器上传速度测试单个文件，上传速度IE>FF>Google(Google浏览器慢相当多，原因：点击查看)    */var fileBox = document.getElementById('file');var reader = null;  //读取操作对象var step = 1024 * 256;  //每次读取文件大小 ,字节数var cuLoaded = 0; //当前已经读取总数var file = null; //当前读取的文件对象var enableRead = true;//标识是否可以读取文件var total = 0;        //记录当前文件总字节数var startTime = null; //标识开始上传时间fileBox.onchange = function () {    //获取文件对象    file = this.files[0];    total = file.size;    console.info("文件大小：" + file.size);    if (ws == null) {        if (window.confirm('建立与服务器链接失败,确定重试链接吗')) {            createSocket(function () {                bindReader();            });        }        return;    }    bindReader();}//绑定readerfunction bindReader() {    cuLoaded = 0;    startTime = new Date();    enableRead = true;    reader = new FileReader();    //读取一段成功    reader.onload = function (e) {        console.info('读取总数：' + e.loaded);        if (enableRead == false)            return false;        //根据当前缓冲区来控制客户端读取速度        if (ws.bufferedAmount > step * 10) {            setTimeout(function () {                //继续读取                console.log('--------------》进入等待');                loadSuccess(e.loaded);            }, 3);        } else {            //继续读取            loadSuccess(e.loaded);        }    }    //开始读取    readBlob();}//读取文件成功处理function loadSuccess(loaded) {    //将分段数据上传到服务器    var blob = reader.result;    //使用WebSocket 服务器发送数据    if (cuLoaded == 0) //发送文件名        ws.send(file.name);    ws.send(blob);    //如果没有读完，继续    cuLoaded += loaded;    if (cuLoaded < total) {        readBlob();    } else {        console.log('总共上传：' + cuLoaded + ',总共用时：' + (new Date().getTime() - startTime.getTime()) / 1000);    }    //显示结果进度    var percent = (cuLoaded / total) * 100;    document.getElementById('Status').innerText = percent;    document.getElementById('progressOne').value = percent;}//指定开始位置，分块读取文件function readBlob() {    //指定开始位置和结束位置读取文件    var blob = file.slice(cuLoaded, cuLoaded + step);    reader.readAsArrayBuffer(blob);}//中止function stop() {    //中止读取操作    console.info('中止，cuLoaded：' + cuLoaded);    enableRead = false;    reader.abort();}//继续function containue() {    console.info('继续，cuLoaded：' + cuLoaded);    enableRead = true;    readBlob();}var ws = null;//创建和服务器的WebSocket 链接function createSocket(onSuccess) {    var url = 'ws://localhost:55373/ashx/upload3.ashx';    ws = new WebSocket(url);    ws.onopen = function () {        console.log('connected成功');        if (onSuccess)            onSuccess();    }    ws.onmessage = function (e) {        var data = e.data;        if (isNaN(data) == false) {            //console.log('当前上传成功：' + data);        } else {            console.info(data);        }    }    ws.onclose = function (e) {        //中止客户端读取        stop();        console.log('链接断开');    }    ws.onerror = function (e) {        //中止客户端读取        stop();        console.info(e);        console.log('传输中发生异常');    }}//页面加载完建立链接createSocket();

更多实例：

分段上传七：

分段上传八：

更多Demo源代码：