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HTML5 文件域+FileReader 分段讀取文件并上傳到服務(wù)器

說(shuō)明：使用Ajax方式上傳，文件不能過(guò)大，最好小于三四百兆，因?yàn)檫^(guò)多的連續(xù)Ajax請(qǐng)求會(huì)使后臺(tái)崩潰，獲取InputStream中數(shù)據(jù)會(huì)為空，尤其在Google瀏覽器測(cè)試過(guò)程中。

1.簡(jiǎn)單分段讀取文件為Blob，ajax上傳到服務(wù)器

<div class="container">
    <div class="panel panel-default">
        <div class="panel-heading">分段讀取文件：</div>
        <div class="panel-body">
            <input type="file" id="file" />
            <blockquote style="word-break:break-all;"></blockquote>
        </div>
    </div>
</div>

JS：

/*
* 分段讀取文件為blob ，并使用ajax上傳到服務(wù)器
* 分段上傳exe文件會(huì)拋出異常
*/
var fileBox = document.getElementById('file');
file.onchange = function () {
    //獲取文件對(duì)象
    var file = this.files[0];
    var reader = new FileReader();
    var step = 1024 * 1024;
    var total = file.size;
    var cuLoaded = 0;
    console.info("文件大?。?quot; + file.size);
    var startTime = new Date();
    //讀取一段成功
    reader.onload = function (e) {
        //處理讀取的結(jié)果
        var loaded = e.loaded;
        //將分段數(shù)據(jù)上傳到服務(wù)器
        uploadFile(reader.result, cuLoaded, function () {
            console.info('loaded:' + cuLoaded + 'current:' + loaded);
            //如果沒(méi)有讀完，繼續(xù)
            cuLoaded += loaded;
            if (cuLoaded < total) {
                readBlob(cuLoaded);
            } else {
                console.log('總共用時(shí)：' + (new Date().getTime() - startTime.getTime()) / 1000);
                cuLoaded = total;
            }
        });
    }
    //指定開(kāi)始位置，分塊讀取文件
    function readBlob(start) {
        //指定開(kāi)始位置和結(jié)束位置讀取文件
        //console.info('start:' + start);
        var blob = file.slice(start, start + step);
        reader.readAsArrayBuffer(blob);
    }
    //開(kāi)始讀取
    readBlob(0);
    //關(guān)鍵代碼上傳到服務(wù)器
    function uploadFile(result, startIndex, onSuccess) {
        var blob = new Blob([result]);
        //提交到服務(wù)器
        var fd = new FormData();
        fd.append('file', blob);
        fd.append('filename', file.name);
        fd.append('loaded', startIndex);
        var xhr = new XMLHttpRequest();
        xhr.open('post', '../ashx/upload2.ashx', true);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                // var data = eval('(' + xhr.responseText + ')');
                console.info(xhr.responseText);
                if (onSuccess)
                    onSuccess();
            }
        }
        //開(kāi)始發(fā)送
        xhr.send(fd);
    }
}

后臺(tái)代碼：

/// <summary>
/// upload2 的摘要說(shuō)明
/// </summary>
public class upload2 : IHttpHandler
{
    LogHelper.LogHelper _log = new LogHelper.LogHelper();
    int totalCount = 0;
    public void ProcessRequest(HttpContext context)
    {
        HttpContext _Context = context;
        //接收文件
        HttpRequest req = _Context.Request;
        if (req.Files.Count <= 0)
        {
            WriteStr("獲取服務(wù)器上傳文件失敗");
            return;
        }
        HttpPostedFile _file = req.Files[0];
        //獲取參數(shù)
        // string ext = req.Form["extention"];
        string filename = req.Form["filename"];
        //如果是int 類(lèi)型當(dāng)文件大的時(shí)候會(huì)出問(wèn)題 最大也就是 1.9999999990686774G
        int loaded = Convert.ToInt32(req.Form["loaded"]);
        totalCount += loaded;

        string newname = @"F:\JavaScript_Solution\H5Solition\H5Solition\Content\TempFile\&;;
        newname += filename;
        //接收二級(jí)制數(shù)據(jù)并保存
        Stream stream = _file.InputStream;
        if (stream.Length <= 0)
            throw new Exception("接收的數(shù)據(jù)不能為空");
        byte[] dataOne = new byte[stream.Length];
        stream.Read(dataOne, 0, dataOne.Length);
        FileStream fs = new FileStream(newname, FileMode.Append, FileAccess.Write, FileShare.Read, 1024);
        try
        {
            fs.Write(dataOne, 0, dataOne.Length);
        }
        finally
        {
            fs.Close();
            stream.Close();
        }
        _log.WriteLine((totalCount + dataOne.Length).ToString());
        WriteStr("分段數(shù)據(jù)保存成功");
    }
    private void WriteStr(string str)
    {
        HttpContext.Current.Response.Write(str); 
    }
    public bool IsReusable
    {
        get
        {
            return true;
        }
    }

2.分段讀取文件為blob ，并使用ajax上傳到服務(wù)器，追加中止、繼續(xù)功能操作

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

JS:

/*
* 分段讀取文件為blob ，并使用ajax上傳到服務(wù)器
* 使用Ajax方式提交上傳數(shù)據(jù)文件大小應(yīng)該有限值，最好500MB以?xún)?nèi)
* 原因短時(shí)間過(guò)多的ajax請(qǐng)求，Asp.Net后臺(tái)會(huì)崩潰獲取上傳的分塊數(shù)據(jù)為空
* 取代方式，長(zhǎng)連接或WebSocket
*/
var fileBox = document.getElementById('file');
var reader = null;  //讀取操作對(duì)象
var step = 1024 * 1024 * 3.5;  //每次讀取文件大小
var cuLoaded = 0; //當(dāng)前已經(jīng)讀取總數(shù)
var file = null; //當(dāng)前讀取的文件對(duì)象
var enableRead = true;//標(biāo)識(shí)是否可以讀取文件
fileBox.onchange = function () {
    //獲取文件對(duì)象
    file = this.files[0];
    var total = file.size;
    console.info("文件大小：" + file.size);
    var startTime = new Date();
    reader = new FileReader();
    //讀取一段成功
    reader.onload = function (e) {
        //處理讀取的結(jié)果
        var result = reader.result;
        var loaded = e.loaded;
        if (enableRead == false)
            return false;
        //將分段數(shù)據(jù)上傳到服務(wù)器
        uploadFile(result, cuLoaded, function () {
            console.info('loaded:' + cuLoaded + '----current:' + loaded);
            //如果沒(méi)有讀完，繼續(xù)
            cuLoaded += loaded;
            if (cuLoaded < total) {
                readBlob(cuLoaded);
            } else {
                console.log('總共用時(shí)：' + (new Date().getTime() - startTime.getTime()) / 1000);
                cuLoaded = total;
            }
            //顯示結(jié)果進(jìn)度
            var percent = (cuLoaded / total) * 100;
            document.getElementById('Status').innerText = percent;
            document.getElementById('progressOne').value = percent;
        });
    }
    //開(kāi)始讀取
    readBlob(0);
    //關(guān)鍵代碼上傳到服務(wù)器
    function uploadFile(result, startIndex, onSuccess) {
        var blob = new Blob([result]);
        //提交到服務(wù)器
        var fd = new FormData();
        fd.append('file', blob);
        fd.append('filename', file.name);
        fd.append('loaded', startIndex);
        var xhr = new XMLHttpRequest();
        xhr.open('post', '../ashx/upload2.ashx', true);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                if (onSuccess)
                    onSuccess();
            } else if (xhr.status == 500) {
                //console.info('請(qǐng)求出錯(cuò)，' + xhr.responseText);
                setTimeout(function () {
                    containue();
                }, 1000);
            }
        }
        //開(kāi)始發(fā)送
        xhr.send(fd);
    }
}
//指定開(kāi)始位置，分塊讀取文件
function readBlob(start) {
    //指定開(kāi)始位置和結(jié)束位置讀取文件
    var blob = file.slice(start, start + step);
    reader.readAsArrayBuffer(blob);
}
//中止
function stop() {
    //中止讀取操作
    console.info('中止，cuLoaded：' + cuLoaded);
    enableRead = false;
    reader.abort();
}
//繼續(xù)
function containue() {
    console.info('繼續(xù)，cuLoaded：' + cuLoaded);
    enableRead = true;
    readBlob(cuLoaded);
}

后臺(tái)代碼同上

3.分段讀取文件為二進(jìn)制數(shù)組，并使用ajax上傳到服務(wù)器

使用二進(jìn)制數(shù)組傳遞的方式，效率特別低，最終文件還與原始大小有些偏差

HTML內(nèi)容同上

JS：

/*
    * 分段讀取文件為二進(jìn)制數(shù)組 ，并使用ajax上傳到服務(wù)器
    * 使用二進(jìn)制數(shù)組傳遞的方式，效率特別低，最終文件還與原始大小有些偏差
    */
var fileBox = document.getElementById('file');
var reader = new FileReader(); //讀取操作對(duì)象
var step = 1024 * 1024;  //每次讀取文件大小
var cuLoaded = 0; //當(dāng)前已經(jīng)讀取總數(shù)
var file = null; //當(dāng)前讀取的文件對(duì)象
var enableRead = true;//標(biāo)識(shí)是否可以讀取文件
fileBox.onchange = function () {
    //獲取文件對(duì)象
    if (file == null) //如果賦值多次會(huì)有丟失數(shù)據(jù)的可能
        file = this.files[0];
    var total = file.size;
    console.info("文件大小：" + file.size);
    var startTime = new Date();
    //讀取一段成功
    reader.onload = function (e) {
        //處理讀取的結(jié)果
        var result = reader.result;
        var loaded = e.loaded;
        if (enableRead == false)
            return false;
        //將分段數(shù)據(jù)上傳到服務(wù)器
        uploadFile(result, cuLoaded, function () {
            console.info('loaded:' + cuLoaded + '----current:' + loaded);
            //如果沒(méi)有讀完，繼續(xù)
            cuLoaded += loaded;
            if (cuLoaded < total) {
                readBlob(cuLoaded);
            } else {
                console.log('總共用時(shí)：' + (new Date().getTime() - startTime.getTime()) / 1000);
                cuLoaded = total;
            }
            //顯示結(jié)果進(jìn)度
            var percent = (cuLoaded / total) * 100;
            document.getElementById('Status').innerText = percent;
            document.getElementById('progressOne').value = percent;
        });
    }
    //開(kāi)始讀取
    readBlob(0);
    //關(guān)鍵代碼上傳到服務(wù)器
    function uploadFile(result, startIndex, onSuccess) {
        var array = new Int8Array(result);
        console.info(array.byteLength);
        //提交到服務(wù)器
        var fd = new FormData();
        fd.append('file', array);
        fd.append('filename', file.name);
        fd.append('loaded', startIndex);
        var xhr = new XMLHttpRequest();
        xhr.open('post', '../ashx/upload3.ashx', true);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                // console.info(xhr.responseText);
                if (onSuccess)
                    onSuccess();
            } else if (xhr.status == 500) {
                console.info('服務(wù)器出錯(cuò)');
                reader.abort();
            }
        }
        //開(kāi)始發(fā)送
        xhr.send(fd);
    }
}
//指定開(kāi)始位置，分塊讀取文件
function readBlob(start) {
    //指定開(kāi)始位置和結(jié)束位置讀取文件
    var blob = file.slice(start, start + step);
    reader.readAsArrayBuffer(blob);
}
//中止
function stop() {
    //中止讀取操作
    console.info('中止，cuLoaded：' + cuLoaded);
    enableRead = false;
    reader.abort();
}
//繼續(xù)
function containue() {
    console.info('繼續(xù)，cuLoaded：' + cuLoaded);
    enableRead = true;
    readBlob(cuLoaded);
}

后臺(tái)代碼：

/// <summary>
/// upload3 的摘要說(shuō)明
/// </summary>
public class upload3 : IHttpHandler
{
    LogHelper.LogHelper _log = new LogHelper.LogHelper();
    int totalCount = 0;
    public void ProcessRequest(HttpContext context)
    {
        HttpContext _Context = context;
        //接收文件
        HttpRequest req = _Context.Request;
        string data = req.Form["file"];
        //轉(zhuǎn)換方式一
        //int[] intData = data.Split(',').Select(q => Convert.ToInt32(q)).ToArray();
        //byte[] dataArray = intData.ToList().ConvertAll(x=>(byte)x).ToArray();
        //轉(zhuǎn)換方式二
        byte[] dataArray = data.Split(',').Select(q => int.Parse(q)).Select(q => (byte)q).ToArray();
        //獲取參數(shù)
        string filename = req.Form["filename"];
        //如果是int 類(lèi)型當(dāng)文件大的時(shí)候會(huì)出問(wèn)題 最大也就是 1.9999999990686774G
        int loaded = Convert.ToInt32(req.Form["loaded"]);
        totalCount += loaded;
        string newname = @"F:\JavaScript_Solution\H5Solition\H5Solition\Content\TempFile\&;;
        newname += filename;
        try
        {
            // 接收二級(jí)制數(shù)據(jù)并保存
            byte[] dataOne = dataArray;
            FileStream fs = new FileStream(newname, FileMode.Append, FileAccess.Write, FileShare.Read, 1024);
            try
            {
                fs.Write(dataOne, 0, dataOne.Length);
            }
            finally
            {
                fs.Close();
            }
            _log.WriteLine((totalCount + dataOne.Length).ToString());
            WriteStr("分段數(shù)據(jù)保存成功");
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
    private void WriteStr(string str)
    {
        HttpContext.Current.Response.Write(str);
    }
    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}

總結(jié)

以上所述是小編給大家介紹的HTML5 文件域+FileReader 分段讀取文件并上傳到服務(wù)器，希望對(duì)大家有所幫助，如果大家有任何疑問(wèn)請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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