說明：使用Ajax方式上傳，文件不能過大，最好小于三四百兆，因為過多的連續Ajax請求會使后臺崩潰，獲取InputStream中數據會為空，尤其在Google瀏覽器測試過程中。
1.簡單分段讀取文件為Blob，ajax上傳到服務器
<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上傳到服務器* 分段上傳exe文件會拋出異常*/var fileBox = document.getElementById('file');file.onchange = function () { //獲取文件對象 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) { //處理讀取的結果 var loaded = e.loaded; //將分段數據上傳到服務器 uploadFile(reader.result, cuLoaded, function () { console.info('loaded:' + cuLoaded + 'current:' + loaded); //如果沒有讀完，繼續 cuLoaded += loaded; if (cuLoaded < total) { readBlob(cuLoaded); } else { console.log('總共用時：' + (new Date().getTime() - startTime.getTime()) / 1000); cuLoaded = total; } }); } //指定開始位置，分塊讀取文件 function readBlob(start) { //指定開始位置和結束位置讀取文件 //console.info('start:' + start); var blob = file.slice(start, start + step); reader.readAsArrayBuffer(blob); } //開始讀取 readBlob(0); //關鍵代碼上傳到服務器 function uploadFile(result, startIndex, onSuccess) { var blob = new Blob([result]); //提交到服務器 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(); } } //開始發送 xhr.send(fd); }} 后臺代碼：
/// <summary>/// upload2 的摘要說明/// </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("獲取服務器上傳文件失敗"); return; } HttpPostedFile _file = req.Files[0]; //獲取參數 // string ext = req.Form["extention"]; string filename = req.Form["filename"]; //如果是int 類型當文件大的時候會出問題 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; //接收二級制數據并保存 Stream stream = _file.InputStream; if (stream.Length <= 0) throw new Exception("接收的數據不能為空"); 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("分段數據保存成功"); } 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上傳到服務器，追加中止、繼續功能操作
<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();" />  <input type="button" value="繼續" 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上傳到服務器* 使用Ajax方式提交上傳數據文件大小應該有限值，最好500MB以內* 原因短時間過多的ajax請求，Asp.Net后臺會崩潰獲取上傳的分塊數據為空* 取代方式，長連接或WebSocket*/var fileBox = document.getElementById('file');var reader = null; //讀取操作對象var step = 1024 * 1024 * 3.5; //每次讀取文件大小var cuLoaded = 0; //當前已經讀取總數var file = null; //當前讀取的文件對象var enableRead = true;//標識是否可以讀取文件fileBox.onchange = function () { //獲取文件對象 file = this.files[0]; var total = file.size; console.info("文件大?。?quot; + file.size); var startTime = new Date(); reader = new FileReader(); //讀取一段成功 reader.onload = function (e) { //處理讀取的結果 var result = reader.result; var loaded = e.loaded; if (enableRead == false) return false; //將分段數據上傳到服務器 uploadFile(result, cuLoaded, function () { console.info('loaded:' + cuLoaded + '----current:' + loaded); //如果沒有讀完，繼續 cuLoaded += loaded; if (cuLoaded < total) { readBlob(cuLoaded); } else { console.log('總共用時：' + (new Date().getTime() - startTime.getTime()) / 1000); cuLoaded = total; } //顯示結果進度 var percent = (cuLoaded / total) * 100; document.getElementById('Status').innerText = percent; document.getElementById('progressOne').value = percent; }); } //開始讀取 readBlob(0); //關鍵代碼上傳到服務器 function uploadFile(result, startIndex, onSuccess) { var blob = new Blob([result]); //提交到服務器 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('請求出錯，' + xhr.responseText); setTimeout(function () { containue(); }, 1000); } } //開始發送 xhr.send(fd); }}//指定開始位置，分塊讀取文件function readBlob(start) { //指定開始位置和結束位置讀取文件 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function containue() { console.info('繼續，cuLoaded：' + cuLoaded); enableRead = true; readBlob(cuLoaded);}后臺代碼同上
3.分段讀取文件為二進制數組 ，并使用ajax上傳到服務器
使用二進制數組傳遞的方式，效率特別低，最終文件還與原始大小有些偏差
HTML內容同上
JS：
/* * 分段讀取文件為二進制數組 ，并使用ajax上傳到服務器 * 使用二進制數組傳遞的方式，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(); //讀取操作對象var step = 1024 * 1024; //每次讀取文件大小var cuLoaded = 0; //當前已經讀取總數var file = null; //當前讀取的文件對象var enableRead = true;//標識是否可以讀取文件fileBox.onchange = function () { //獲取文件對象 if (file == null) //如果賦值多次會有丟失數據的可能 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) { //處理讀取的結果 var result = reader.result; var loaded = e.loaded; if (enableRead == false) return false; //將分段數據上傳到服務器 uploadFile(result, cuLoaded, function () { console.info('loaded:' + cuLoaded + '----current:' + loaded); //如果沒有讀完，繼續 cuLoaded += loaded; if (cuLoaded < total) { readBlob(cuLoaded); } else { console.log('總共用時：' + (new Date().getTime() - startTime.getTime()) / 1000); cuLoaded = total; } //顯示結果進度 var percent = (cuLoaded / total) * 100; document.getElementById('Status').innerText = percent; document.getElementById('progressOne').value = percent; }); } //開始讀取 readBlob(0); //關鍵代碼上傳到服務器 function uploadFile(result, startIndex, onSuccess) { var array = new Int8Array(result); console.info(array.byteLength); //提交到服務器 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('服務器出錯'); reader.abort(); } } //開始發送 xhr.send(fd); }}//指定開始位置，分塊讀取文件function readBlob(start) { //指定開始位置和結束位置讀取文件 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function containue() { console.info('繼續，cuLoaded：' + cuLoaded); enableRead = true; readBlob(cuLoaded);}后臺代碼：
/// <summary>/// upload3 的摘要說明/// </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"]; //轉換方式一 //int[] intData = data.Split(',').Select(q => Convert.ToInt32(q)).ToArray(); //byte[] dataArray = intData.ToList().ConvertAll(x=>(byte)x).ToArray(); //轉換方式二 byte[] dataArray = data.Split(',').Select(q => int.Parse(q)).Select(q => (byte)q).ToArray(); //獲取參數 string filename = req.Form["filename"]; //如果是int 類型當文件大的時候會出問題 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 { // 接收二級制數據并保存 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("分段數據保存成功"); } catch (Exception ex) { throw ex; } } private void WriteStr(string str) { HttpContext.Current.Response.Write(str); } public bool IsReusable { get { return false; } }}總結
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器，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對VeVb武林網網站的支持！
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