jQuery 利用$.ajax 时获取原生XMLHttpRequest 对象的方法

<script> 
$('.screenshot_input').change(function (){ 
//获取file对象 即相当于可以直接post的$_FILES数据 
var domFile = $(this)[0].files[0] 
var domForm = $('#testForm')[0] 
//将form对象直接作为参数 new FormData对象 
var formData = new FormData(domForm); 
//追加file 对象 
formData.append('file',domFile); 
$.ajax({ 
url:'{{ path( 'acme_admin_app_dealAppScreenShot') }}', 
type: "POST", 
data: formData, 
processData: false, // tell jQuery not to process the data 
contentType: false, // tell jQuery not to set contentType 
xhr: function(){ //这是关键 获取原生的xhr对象 做以前做的所有事情 
var xhr = jQuery.ajaxSettings.xhr(); 
xhr.upload.onload = function (){ 
alert('finish downloading') 
} 
xhr.upload.onprogress = function (ev) { 
if(ev.lengthComputable) { 
var percent = 100 * ev.loaded/ev.total; 
console.log(percent,ev) 
} 
} 
return xhr; 
}, 
success:function(data){ 
alert(data) 
} 
}) 
}) 
</script> 
Array 
( 
[name] => cooff 
[email] => qq.comaa 
) 
Array 
( 
[file] => Array 
( 
[name] => yunce2.0测试.apk 
[type] => application/vnd.android.package-archive 
[tmp_name] => /tmp/php4Jxt0c 
[error] => 0 
[size] => 6476627 
) 
)