ajaxFileUpload 上传文件/图片，传参数，解决第二次无法上传问题

html:

<script charset="utf-8" src="js/ajaxfileupload.js"></script>

<input style="display:;" type="file" id="userfile" onchange="ajaxFileUpload('userfile')" value="" name="userfile" />

Javascript:

var count = 1;
function ajaxFileUpload(id){
count++;
//图片格式验证
var x = $('#'+id);
if (!x || !x.val()) return;
var patn = /\.jpg$|\.jpeg$|\.png$|\.gif$/i;
if (!patn.test(x.val())) {
alert("您选择的不是图片");
x.val() = "";
return;
}

$.ajaxFileUpload({
url: "upload.php",//上传的url，自己设置
type: 'post',
secureuri: false, //一般设置为false
fileElementId: id, // 上传文件的id、name属性名
dataType: 'text', //返回值类型，一般设置为json、application/json
data: {'userfile':id,'time':new Date().getTime()},//传参
success: function (data, status) {
data = data.replace(/<.*?>/g,'');
var obj = eval('(' + data + ')');
if(obj.url == ''){
alert(obj.msg);
return;
}

$('#userfile').attr('title',count);

},
error: function (data, status, e) {
//alert('[未知错误]'+e);
$('#userfile').attr('title',count);
}
});
//return false;
}

* 加上  $('#userfile').attr('title',count); 这句，解决第二次上传同一个文件名的文件没有反应的问题。

ajaxfileupload.js（下载：http://download.csdn.net/download/macwhirr123/9730450）

// JavaScript Document
jQuery.extend({

createUploadIframe: function(id, uri)
{
//create frame
var frameId = 'jUploadFrame' + id;

if(window.ActiveXObject) {
if(jQuery.browser.version=="9.0") {
io = document.createElement('iframe');
io.id = frameId;
io.name = frameId;
} else if(jQuery.browser.version=="6.0"||jQuery.browser.version=="7.0"||jQuery.browser.version=="8.0") {
var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
if(typeof uri== 'boolean'){
io.src = 'javascript:false';
}
else if(typeof uri== 'string'){
io.src = uri;
}
}
}
else {
var io = document.createElement('iframe');
io.id = frameId;
io.name = frameId;
}
io.style.position = 'absolute';
io.style.top = '-1000px';
io.style.left = '-1000px';

document.body.appendChild(io);

return io;
},
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>');
var oldElement = jQuery('#' + fileElementId);
var newElement = jQuery(oldElement).clone();
jQuery(oldElement).attr('id', fileId);
jQuery(oldElement).before(newElement);
jQuery(oldElement).appendTo(form);
/*
var oldElement = jQuery('#' + fileElementId);
var newElement = oldElement.clone(true);
newElement[0].files=oldElement[0].files;
oldElement.attr('id', fileId);
oldElement.before(newElement);
oldElement.appendTo(form);*/

//增加文本参数的支持
if (data) {
for (var i in data) {
$('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').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 = s.fileElementId;
var form = jQuery.createUploadForm(id, s.fileElementId,s.data);
var io = jQuery.createUploadIframe(id, s.secureuri);
var frameId = 'jUploadFrame' + id;
var formId = 'jUploadForm' + id;

if( s.global && ! jQuery.active++ )
{
// Watch for a new set of requests
jQuery.event.trigger( "ajaxStart" );
}
var requestDone = false;
// Create the request object
var xml = {};
if( s.global )
{
jQuery.event.trigger("ajaxSend", [xml, s]);
}

var uploadCallback = function(isTimeout)
{
// Wait for a response to come back
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( s.success )
{
// ifa local callback was specified, fire it and pass it the data
s.success( data, status );
};
if( s.global )
{
// Fire the global callback
jQuery.event.trigger( "ajaxSuccess", [xml, s] );
};
} else
{
jQuery.handleError(s, xml, status);
}

} catch(e)
{
status = "error";
jQuery.handleError(s, xml, status, e);
};
if( s.global )
{
// The request was completed
jQuery.event.trigger( "ajaxComplete", [xml, s] );
};

// Handle the global AJAX counter
if(s.global && ! --jQuery.active)
{
jQuery.event.trigger("ajaxStop");
};
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(){

if( !requestDone )
{
// Check to see ifthe request is still happening
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)
{
form.encoding = 'multipart/form-data';
}
else
{
form.enctype = 'multipart/form-data';
}
jQuery(form).submit();

} catch(e)
{
jQuery.handleError(s, xml, null, e);
}
if(window.attachEvent){
document.getElementById(frameId).attachEvent('onload', uploadCallback);
}
else{
document.getElementById(frameId).addEventListener('load', uploadCallback, false);
}
return {abort: function () {}};

},

uploadHttpData: function( r, type ) {
var data = !type;
data = type == "xml" || data ? r.responseXML : r.responseText;
// ifthe type is "script", eval it in global context
if( type == "script" )
{
jQuery.globalEval( data );
}

// Get the JavaScript object, ifJSON is used.
if( type == "json" )
{
eval( "data = " + data );
}

// evaluate scripts within html
if( type == "html" )
{
jQuery("<div>").html(data).evalScripts();
}

return data;
}

,

handleError: function (s, xhr, status, e) {
if (s.error) {
s.error.call(s.context || s, xhr, status, e);
}
if (s.global) {
(s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
}
},
httpData: function (xhr, type, s) {
var ct = xhr.getResponseHeader("content-type"),
xml = type == "xml" || !type && ct && ct.indexOf("xml") >= 0,
data = xml ? xhr.responseXML : xhr.responseText;
if (xml && data.documentElement.tagName == "parsererror")
throw "parsererror";
if (s && s.dataFilter)
data = s.dataFilter(data, type);
if (typeof data === "string") {
if (type == "script")
jQuery.globalEval(data);
if (type == "json")
data = window["eval"]("(" + data + ")");
}
return data;
}

});