ajaxFileUpload 无刷新上传的原理：
在页面动态创建 form 表单和 ifram 贞，设定 form 表单提交的目标为 ifram 贞，
将文件域和要 post 的参数动态写入 form 表单中，然后提交 from 表单。
通过 window.attachEvent 向 ifram 贞的 onload 事件中注册监听事件响应回调函数。
1.html 部分
[html] view plaincopy
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<input name="imgfile1" id="imgfile1" style="width: 200px; height: 25px;" size="38" type="file" />
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<div id="imgContainer1"></div>
2.调用部分
[javascript] view plaincopy
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function uploadImg(imgfileId, imgcontainerId) {
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$.ajaxFileUpload({
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fileElementId: imgfileId,
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url: '/UploadImage',
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dataType: 'json',
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data: { id: 'aaa', name: 'bbb' },
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beforeSend: function (XMLHttpRequest) {
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//("loading");
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},
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success: function (data, textStatus) {
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var img = "<img src='' width='300' height='300' />";
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$("#" + imgcontainerId).append(img);
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},
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error: function (XMLHttpRequest, textStatus, errorThrown) {
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var img = "图片上传失败！";
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$("#" + imgcontainerId).append(img);
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var msg = "服务器出错，错误内容：" + XMLHttpRequest.responseText;
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$.messager.showWin({ msg: msg, title: '错误提示', color: 'red' });
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},
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complete: function (XMLHttpRequest, textStatus) {
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//("loaded");
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}
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});
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}
3.ajaxFileUpload.js 全部代码
[javascript] view plaincopy
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/*
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131108-xxj-ajaxFileUpload.js 无刷新上传图片 jquery 插件，支持 ie6-ie10
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依赖：jquery-1.6.1.min.js
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主方法：ajaxFileUpload 接受 json 对象参数
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参数说明：
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fileElementId：必选,上传文件域ID
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url：必选，发送请求的URL字符串
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fileFilter：可选，限定上传文件的格式（.jpg,.bmp,.gif,.png）
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fileSize:可选，0 为无限制(IE浏览器不兼容)
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data:可选，将和文件域一同post的参数（json对象）
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其它：$.ajax 的参数均为可选参数
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注：如遇到‘无法访问’的脚本错误提示则需要在响应流中加一段脚块一同输出：<script ...>document.domain = 'xxx.com';</script>
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*/
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jQuery.extend({
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//创建 iframe 元素,接受提交及响应
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createUploadIframe: function(id, uri) {
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//create frame
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var frameId = 'jUploadFrame' + id;
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if (window.ActiveXObject) {
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//fix ie9 and ie 10-------------
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if (jQuery.browser.version == "9.0" || jQuery.browser.version == "10.0") {
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var io = document.createElement('iframe');
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io.id = frameId;
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io.name = frameId;
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} else if (jQuery.browser.version == "6.0" || jQuery.browser.version == "7.0" || jQuery.browser.version == "8.0") {
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var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
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if (typeof uri == 'boolean') {
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io.src = 'javascript:false';
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} else if (typeof uri == 'string') {
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io.src = uri;
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}
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}
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} else {
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var io = document.createElement('iframe');
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io.id = frameId;
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io.name = frameId;
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}
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io.style.position = 'absolute';
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io.style.top = '-1000px';
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io.style.left = '-1000px';
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document.body.appendChild(io);
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return io;
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},
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//创建 from 元素，用于提交的表单
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createUploadForm: function(id, fileElementId, postData) {
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//create form<span style="white-space:pre"> </span>
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var formId = 'jUploadForm' + id;
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var fileId = 'jUploadFile' + id;
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var form = $('<form action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');
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var oldElement = $('#' + fileElementId);
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var newElement = $(oldElement).clone();
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$(oldElement).attr('id', fileId);
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$(oldElement).before(newElement);
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$(oldElement).appendTo(form);
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//添加自定义参数
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if (postData) {
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//递归遍历JSON所有键值
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function recurJson(json) {
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for (var i in json) {
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//alert(i+"="+json[i])
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$("<input name='" + i + "' id='" + i + "' value='" + json[i] + "' />").appendTo(form);
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if (typeof json[i] == "object") {
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recurJson(json[i]);
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}
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}
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}
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recurJson(postData);
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}
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//set attributes
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$(form).css('position', 'absolute');
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$(form).css('top', '-1200px');
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$(form).css('left', '-1200px');
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$(form).appendTo('body');
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return form;
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},
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//上传文件
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//s 参数：json对象
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ajaxFileUpload: function(s) {
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s = jQuery.extend({fileFilter:"",fileSize:0}, jQuery.ajaxSettings, s);
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//文件筛选
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var fielName = $('#' + s.fileElementId).val();
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var extention = fielName.substring(fielName.lastIndexOf(".") + 1).toLowerCase();
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if (s.fileFilter && s.fileFilter.indexOf(extention) < 0) {
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alert("仅支持 (" + s.fileFilter + ") 为后缀名的文件!");
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return;
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}
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//文件大小限制
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if (s.fileSize > 0) {
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var fs = 0;
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try {
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if (window.ActiveXObject) {
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//IE浏览器
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var image = new Image();
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image.dynsrc = fielName;
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fs = image.fileSize;
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} else {
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fs = $('#' + s.fileElementId)[0].files[0].size;
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}
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} catch(e) {
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}
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if (fs > s.fileSize) {
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alert("当前文件大小 (" + fs + ") 超过允许的限制值 (" + s.fileSize +")！");
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return;
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}
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}
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var id = new Date().getTime();
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//创建 form 表单元素
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var form = jQuery.createUploadForm(id, s.fileElementId, s.data);
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//创建 iframe 贞元素
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var io = jQuery.createUploadIframe(id, s.secureuri);
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var frameId = 'jUploadFrame' + id;
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var formId = 'jUploadForm' + id;
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//监测是否有新的请求
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if (s.global && !jQuery.active++) {
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jQuery.event.trigger("ajaxStart"); //触发 AJAX 请求开始时执行函数。Ajax 事件。
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}
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var requestDone = false;
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//创建请求对象
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var xml = {};
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if (s.global)
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jQuery.event.trigger("ajaxSend", [xml, s]); //触发 AJAX 请求发送前事件
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//上载完成的回调函数
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var uploadCallback = function(isTimeout) {
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var io = document.getElementById(frameId);
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try {
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//存在跨域脚本访问问题，如遇到‘无法访问’提示则需要在响应流中加一段脚块：<script ...>document.domain = 'xxx.com';</script>
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if (io.contentWindow) { //兼容各个浏览器，可取得子窗口的 window 对象
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xml.responseText = io.contentWindow.document.body ? io.contentWindow.document.body.innerHTML : null;
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xml.responseXML = io.contentWindow.document.XMLDocument ? io.contentWindow.document.XMLDocument : io.contentWindow.document;
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} else if (io.contentDocument) { //contentDocument Firefox 支持，> ie8 的ie支持。可取得子窗口的 document 对象。
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xml.responseText = io.contentDocument.document.body ? io.contentDocument.document.body.innerHTML : null;
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xml.responseXML = io.contentDocument.document.XMLDocument ? io.contentDocument.document.XMLDocument : io.contentDocument.document;
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}
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} catch(e) {
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jQuery.handleErrorExt(s, xml, null, e);
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}
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if (xml || isTimeout == "timeout") {
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requestDone = true;
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var status;
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try {
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status = isTimeout != "timeout" ? "success" : "error";
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// Make sure that the request was successful or notmodified
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if (status != "error") {
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//处理数据（运行XML通过httpData不管回调）
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var data = jQuery.uploadHttpData(xml, s.dataType);
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// If a local callback was specified, fire it and pass it the data
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if (s.success)
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s.success(data, status);
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// Fire the global callback
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if (s.global)
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jQuery.event.trigger("ajaxSuccess", [xml, s]);
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} else
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jQuery.handleErrorExt(s, xml, status);
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} catch(e) {
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status = "error";
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jQuery.handleErrorExt(s, xml, status, e);
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}
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// The request was completed
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if (s.global)
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jQuery.event.trigger("ajaxComplete", [xml, s]);
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// Handle the global AJAX counter
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if (s.global && !--jQuery.active)
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jQuery.event.trigger("ajaxStop");
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// Process result
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if (s.complete)
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s.complete(xml, status);
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jQuery(io).unbind();
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setTimeout(function() {
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try {
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$(io).remove();
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$(form).remove();
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} catch(e) {
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jQuery.handleErrorExt(s, xml, null, e);
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}
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}, 100);
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xml = null;
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}
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};
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//超时检查，s.timeout 毫秒后调用 uploadCallback 回调函数提示请求超时
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if (s.timeout > 0) {
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setTimeout(function() {
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// Check to see if the request is still happening
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if (!requestDone) uploadCallback("timeout");
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}, s.timeout);
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}
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try {
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//设置动态 form 表单的提交参数
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// var io = $('#' + frameId);
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var form = $('#' + formId);
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$(form).attr('action', s.url);
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$(form).attr('method', 'POST');
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$(form).attr('target', frameId);
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if (form.encoding) {
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form.encoding = 'multipart/form-data';
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} else {
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form.enctype = 'multipart/form-data';
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}
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$(form).submit();
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} catch(e) {
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jQuery.handleErrorExt(s, xml, null, e);
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}
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//向动态表单的页面加载事件中注册回调函数
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if (window.attachEvent) {
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document.getElementById(frameId).attachEvent('onload', uploadCallback);
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} else {
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document.getElementById(frameId).addEventListener('load', uploadCallback, false);
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}
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return {
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abort: function() {
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}
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};
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},
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//上传文件
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uploadHttpData: function(r, type) {
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//alert("type=" + type + ";uploadHttpData" + JSON.stringify(r))
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var data = !type;
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data = type == "xml" || data ? r.responseXML : r.responseText;
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// If the type is "script", eval it in global context
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if (type == "script")
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jQuery.globalEval(data);
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// Get the JavaScript object, if JSON is used.
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if (type == "json")
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eval("data = " + data);
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// evaluate scripts within html
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if (type == "html")
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jQuery("<div>").html(data).evalScripts();
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//alert($('param', data).each(function(){alert($(this).attr('value'));}));
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return data;
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},
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handleErrorExt: function(s, xhr, status, e) {
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// If a local callback was specified, fire it
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if (s.error) {
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s.error.call(s.context || s, xhr, status, e);
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}
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// Fire the global callback
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if (s.global) {
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(s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
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}
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}
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});
