JavaScript File分段上传

<form method="POST" name="form" action="/mupload/upload/" enctype="multipart/form-data"><input type='hidden' name='csrfmiddlewaretoken' value='' /><input id='file' type='file' name='file' onchange="" /><input id='button' name='submit' type='button' value="上传" onclick="chunk_upload(this)"/></form> 

var fileSplitSize = 1024 * 1024;var start=0,end=0;var i=0;// 文件段上传function chunk_upload(button){var xmlhttp = new XMLHttpRequest();xmlhttp.open("POST", "/chunk_upload/upload/", false);xmlhttp.setRequestHeader("X-CSRFToken", button.form['csrfmiddlewaretoken'].value);var f = button.form;var file = f['file']['files'][0];var size=file.size;end=start+fileSplitSize;if(end>size){i=-1;end=size;}else{i+=1;end=end;}<br>　　//按大小切割文件段var blob = file.slice(start, end);xmlhttp.setRequestHeader('charset','utf-8');xmlhttp.setRequestHeader("fileMD5", fileMD5);xmlhttp.setRequestHeader("start", start);xmlhttp.setRequestHeader("end", end);xmlhttp.send(blob);if(xmlhttp.status==200){<br> if(end==size){<br> var backtext=xmlhttp.responseText;<br> alert(backtext);<br> }else{<br> alert("上传完成第"+i+"段")<br> start=end;<br> chunk_upload(button);<br> }<br> }else{<br> alert("上传错误");<br> chunk_upload(button);<br> }} 

;(function(window,document){var myUpload = function(option) {var file,fd = new FormData(),xhr = new XMLHttpRequest(),loaded, tot, per, uploadUrl,input;input = document.createElement("input");input.setAttribute('id',"myUpload-input");input.setAttribute('type',"file");input.setAttribute('name',"files");input.click();uploadUrl = option.uploadUrl;callback = option.callback;uploading = option.uploading;beforeSend = option.beforeSend;input.onchange= function(){file = input.files[0];if(beforeSend instanceof Function){if(beforeSend(file) === false){return false;}}fd.append("files", file);xhr.onreadystatechange = function() {if (xhr.readyState == 4 && xhr.status == 200) {if(callback instanceof Function){callback(xhr.responseText);}}}//侦查当前附件上传情况xhr.upload.onprogress = function(evt) {loaded = evt.loaded;tot = evt.total;per = Math.floor(100 * loaded / tot); //已经上传的百分比if(uploading instanceof Function){uploading(per);}};xhr.open("post", uploadUrl);xhr.send(fd);}};window.myUpload = myUpload;})(window,document);//用法//触发文件上传事件myUpload({//上传文件接收地址uploadUrl: "/async/myUpload.php",//选择文件后，发送文件前自定义事件//file为上传的文件信息，可在此处做文件检测、初始化进度条等动作beforeSend: function(file) {},//文件上传完成后回调函数//res为文件上传信息callback: function(res) {},//返回上传过程中包括上传进度的相关信息//详细请看res,可在此加入进度条相关代码uploading: function(res) {}});