说明:使用Ajax方式上传,文件不能过大,最好小于三四百兆,因为过多的连续Ajax请求会使后台崩溃,获取InputStream中数据会为空,尤其在Google浏览器测试过程中。
1.简单分段读取文件为Blob,ajax上传到服务器
<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" /> <blockquote style="word-break:break-all;"></blockquote> </div> </div> </div>
JS:
/* * 分段读取文件为blob ,并使用ajax上传到服务器 * 分段上传exe文件会抛出异常 */ var fileBox = document.getElementById('file'); file.onchange = function () { //获取文件对象 var file = this.files[0]; var reader = new FileReader(); var step = 1024 * 1024; var total = file.size; var cuLoaded = 0; console.info("文件大小:" + file.size); var startTime = new Date(); //读取一段成功 reader.onload = function (e) { //处理读取的结果 var loaded = e.loaded; //将分段数据上传到服务器 uploadFile(reader.result, cuLoaded, function () { console.info('loaded:' + cuLoaded + 'current:' + loaded); //如果没有读完,继续 cuLoaded += loaded; if (cuLoaded < total) { readBlob(cuLoaded); } else { console.log('总共用时:' + (new Date().getTime() - startTime.getTime()) / 1000); cuLoaded = total; } }); } //指定开始位置,分块读取文件 function readBlob(start) { //指定开始位置和结束位置读取文件 //console.info('start:' + start); var blob = file.slice(start, start + step); reader.readAsArrayBuffer(blob); } //开始读取 readBlob(0); //关键代码上传到服务器 function uploadFile(result, startIndex, onSuccess) { var blob = new Blob([result]); //提交到服务器 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(); } } //开始发送 xhr.send(fd); } }
后台代码:
/// <summary> /// upload2 的摘要说明 /// </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("获取服务器上传文件失败"); return; } HttpPostedFile _file = req.Files[0]; //获取参数 // string ext = req.Form["extention"]; string filename = req.Form["filename"]; //如果是int 类型当文件大的时候会出问题 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; //接收二级制数据并保存 Stream stream = _file.InputStream; if (stream.Length <= 0) throw new Exception("接收的数据不能为空"); 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("分段数据保存成功"); } private void WriteStr(string str) { HttpContext.Current.Response.Write(str); } public bool IsReusable { get { return true; } }
2.分段读取文件为blob ,并使用ajax上传到服务器,追加中止、继续功能 *** 作
<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();" /> <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:
/* * 分段读取文件为blob ,并使用ajax上传到服务器 * 使用Ajax方式提交上传数据文件大小应该有限值,最好500MB以内 * 原因短时间过多的ajax请求,Asp.Net后台会崩溃获取上传的分块数据为空 * 取代方式,长连接或WebSocket */ var fileBox = document.getElementById('file'); var reader = null; //读取 *** 作对象 var step = 1024 * 1024 * 3.5; //每次读取文件大小 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 fileBox.onchange = function () { //获取文件对象 file = this.files[0]; var total = file.size; console.info("文件大小:" + file.size); var startTime = new Date(); reader = new FileReader(); //读取一段成功 reader.onload = function (e) { //处理读取的结果 var result = reader.result; var loaded = e.loaded; if (enableRead == false) return false; //将分段数据上传到服务器 uploadFile(result, cuLoaded, function () { console.info('loaded:' + cuLoaded + '----current:' + loaded); //如果没有读完,继续 cuLoaded += loaded; if (cuLoaded < total) { readBlob(cuLoaded); } else { console.log('总共用时:' + (new Date().getTime() - startTime.getTime()) / 1000); cuLoaded = total; } //显示结果进度 var percent = (cuLoaded / total) * 100; document.getElementById('Status').innerText = percent; document.getElementById('progressOne').value = percent; }); } //开始读取 readBlob(0); //关键代码上传到服务器 function uploadFile(result, startIndex, onSuccess) { var blob = new Blob([result]); //提交到服务器 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('请求出错,' + xhr.responseText); setTimeout(function () { containue(); }, 1000); } } //开始发送 xhr.send(fd); } } //指定开始位置,分块读取文件 function readBlob(start) { //指定开始位置和结束位置读取文件 var blob = file.slice(start, start + step); reader.readAsArrayBuffer(blob); } //中止 function stop() { //中止读取 *** 作 console.info('中止,cuLoaded:' + cuLoaded); enableRead = false; reader.abort(); } //继续 function containue() { console.info('继续,cuLoaded:' + cuLoaded); enableRead = true; readBlob(cuLoaded); }
后台代码同上
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以上就是H5的文件域FileReader怎样分段读取文件上传到服务器的详细内容,
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