HTML5 文件域+FileReader 分段读取文件并上传(七)-WebSocket-蒲公英云

一、单文件上传实例

HTML：

复制代码

<div class="container">
    <div class="panel panel-default">
        <div class="panel-heading">分段读取文件：</div>
        <div class="panel-body">
            <input type="file" id="file" /><br />
            <input type="button" value="中止" onclick="stop();" />∅
            <input type="button" value="继续" onclick="containue();" />
            <progress id="progressOne" style="width:400px;" max="100" value="0"></progress>
            <blockquote id="Status" style="word-break:break-all;"></blockquote>
        </div>
    </div>
</div>

复制代码

JS：

复制代码

/*
    * 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)
    */
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reader
function 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();

复制代码

服务器后台处理：

复制代码

public void ProcessRequest(HttpContext context)
    {
        //处理WebSocket 请求
        context.AcceptWebSocketRequest(DoWork);
    }
    /// <summary>
    /// 委托处理函数定义
    /// </summary>
    /// <param name="context">当前WebSocket上下文</param>
    /// <returns></returns>
    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<byte> buffer = new ArraySegment<byte>(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<byte>(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<byte>(Encoding.UTF8.GetBytes(curLength.ToString()));
                    await socket.SendAsync(buffer, WebSocketMessageType.Text, true, CancellationToken.None);
                }
            }
            else { break; }
        }
    }
    /// <summary>
    /// 追加二进制数据到文件
    /// </summary>
    public string SaveFile(string file, ArraySegment<byte> 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;
        }
    }