Ajax文件上传插件很多，但兼容性各不一样，许多是对ie不兼容的，另外项目中是要求将网页内容嵌入到桌面端应用的，这样就不允许带flash的上传插件了，如：jquery uploadify。。。悲剧
对于Ajax文件上传，大体是有：
1、创建一个input type="file" 的文件上传按钮，根据其id监听绑定其change事件，在事件中用jquery创建一个iframe，嵌入添加隐藏form，同时创建input type="file"，id相同的文件上传按钮，并传入其他需要提交的数据，然后提交，提交完成后移除一个input type="file"，这样用bind或on的绑定就对新的input 框失效，需要重新再绑定一次change事件，以前的jquery是可以使用live函数代替的，现在只能在文件上传成功后再绑定一次change事件。
$(function() {
uploadFile("fileData",'cn.ftiao.cm.model.LiveCourse','',"CI");
});
function uploadFile(id,classFullName,jsonStrValue,preFileName){
$("#"+id).on("change", function(){
// 上传方法
$.ajaxFileUpload({
url:$("#"+id).attr("data-url-upload"), //需要链接到服务器地址
secureuri:false,
type:"post",
fileElementId:id, //文件选择框的id属性
dataType: 'json',
data:{
"classFullName":classFullName,
"jsonStrValue":"",
"preFileName":preFileName
},
//服务器返回的格式，可以是json
success: function (data, status){ //相当于java中try语句块的用法
$("#courseIconImg").attr("src",$(".ctx").val()+"/images/img-class.png");
alert("hello");
//先将原有的上传展示清除
$("#" + id).nextAll("span").remove();
$("#courseIcon").val(data.outputFileName);
// $("#coursewareFile").val(data.outputFileName);
var uploadHtml = "<span id='"+data.outputPreFileName+"_livelesson_div' style='color:#FFFFFF;'>";
uploadHtml += data.fileUploadName ;
uploadHtml += "<a name='_LIVELESSON_PRIVIEW'> 预览 </a><a name='_LIVELESSON_DEL'> 删除 </a>";
uploadHtml += "</span>";
// $("#"+id).parents("li").append(uploadHtml);
uploadFile("fileData",'cn.ftiao.cm.model.LiveCourse','',"CI");
},
error: function (data, status, e) //相当于java中catch语句块的用法
{
alert(e);
}
});
});
return false;
}
2、创建一个 input type="file"的按钮，监听其click事件，然后创建iframe，隐藏form，隐藏form里有个 input type="file"的文件上传框，模拟点击click，弹出文件选择框，选择完文件后上传。此方法在ie下会报 “权限不足” 问题。
下面是ajaxFileUpload 插件
jQuery.extend({
handleError: function(s, xhr, status, e) {
// If a local callback was specified, fire it
if (s.error) {
s.error.call(s.context || window, xhr, status, e);
}
// Fire the global callback
if (s.global) {
(s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
}
},
createUploadIframe: function(id, uri)
{
//create frame
var frameId = 'jUploadFrame' + id;
var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
if(window.ActiveXObject)
{
if(typeof uri== 'boolean'){
iframeHtml += ' src="' + 'javascript:false' + '"';
}
else if(typeof uri== 'string'){
iframeHtml += ' src="' + uri + '"';
}
}
iframeHtml += ' />';
jQuery(iframeHtml).appendTo(document.body);
return jQuery('#' + frameId).get(0);
},
createUploadForm: function(id, fileElementId, data)
{
//create form
var formId = 'jUploadForm' + id;
var fileId = 'jUploadFile' + id;
var form = jQuery('<form action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');
if(data)
{
for(var i in data)
{
jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
}
}
var oldElement = jQuery('#' + fileElementId);
var newElement = jQuery(oldElement).clone();
jQuery(oldElement).attr('id', fileId);
jQuery(oldElement).before(newElement);
jQuery(oldElement).appendTo(form);
//set attributes
jQuery(form).css('position', 'absolute');
jQuery(form).css('top', '-1200px');
jQuery(form).css('left', '-1200px');
jQuery(form).appendTo('body');
return form;
},
ajaxFileUpload: function(s) {
// TODO introduce global settings, allowing the client to modify them for all requests, not only timeout
s = jQuery.extend({}, jQuery.ajaxSettings, s);
var id = new Date().getTime()
var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data)=='undefined'?false:s.data));
var io = jQuery.createUploadIframe(id, s.secureuri);
var frameId = 'jUploadFrame' + id;
var formId = 'jUploadForm' + id;
// Watch for a new set of requests
if ( s.global && ! jQuery.active++ )
{
jQuery.event.trigger( "ajaxStart" );
}
var requestDone = false;
// Create the request object
var xml = {}
if ( s.global )
jQuery.event.trigger("ajaxSend", [xml, s]);
// Wait for a response to come back
var uploadCallback = function(isTimeout)
{
var io = document.getElementById(frameId);
try
{
if(io.contentWindow)
{
xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
}else if(io.contentDocument)
{
xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
}
}catch(e)
{
jQuery.handleError(s, xml, null, e);
}
if ( xml || isTimeout == "timeout")
{
requestDone = true;
var status;
try {
status = isTimeout != "timeout" ? "success" : "error";
// Make sure that the request was successful or notmodified
if ( status != "error" )
{
// process the data (runs the xml through httpData regardless of callback)
var data = jQuery.uploadHttpData( xml, s.dataType );
// If a local callback was specified, fire it and pass it the data
if ( s.success )
s.success( data, status );
// Fire the global callback
if( s.global )
jQuery.event.trigger( "ajaxSuccess", [xml, s] );
} else
jQuery.handleError(s, xml, status);
} catch(e)
{
status = "error";
jQuery.handleError(s, xml, status, e);
}
// The request was completed
if( s.global )
jQuery.event.trigger( "ajaxComplete", [xml, s] );
// Handle the global AJAX counter
if ( s.global && ! --jQuery.active )
jQuery.event.trigger( "ajaxStop" );
// Process result
if ( s.complete )
s.complete(xml, status);
jQuery(io).unbind()
setTimeout(function()
{ try
{
jQuery(io).remove();
jQuery(form).remove();
} catch(e)
{
jQuery.handleError(s, xml, null, e);
}
}, 100)
xml = null
}
}
// Timeout checker
if ( s.timeout > 0 )
{
setTimeout(function(){
// Check to see if the request is still happening
if( !requestDone ) uploadCallback( "timeout" );
}, s.timeout);
}
try
{
var form = jQuery('#' + formId);
jQuery(form).attr('action', s.url);
jQuery(form).attr('method', 'POST');
jQuery(form).attr('target', frameId);
if(form.encoding)
{
jQuery(form).attr('encoding', 'multipart/form-data');
}
else
{
jQuery(form).attr('enctype', 'multipart/form-data');
}
jQuery(form).submit();
} catch(e)
{
jQuery.handleError(s, xml, null, e);
}
jQuery('#' + frameId).load(uploadCallback );
return {abort: function () {}};
},
uploadHttpData: function( r, type ) {
var data = !type;
data = type == "xml" || data ? r.responseXML : r.responseText;
// If the type is "script", eval it in global context
if ( type == "script" )
jQuery.globalEval( data );
// Get the JavaScript object, if JSON is used.
if (type == "json"){
if (data.indexOf("<") >= 0) {
data = jQuery.parseJSON(jQuery(data).text());
}
else {
eval("data = " + data); /*Bug fixed by under */
}
}
// evaluate scripts within html
if ( type == "html" )
jQuery("<div>").html(data).evalScripts();
return data;
}
})