jQuery异步上传表单（包含文件）

var formData = new FormData($('form')[0]);
$.ajax({
url: 'URL',  // Server script to process data
type: 'POST',
xhr: function() {
// Custom XMLHttpRequest
var myXhr = $.ajaxSettings.xhr()
// Check if upload property exists
if (myXhr.upload) {
// For handling the progress of the upload
myXhr.upload.addEventListener('progress', progressHandlingFunction, false);
}
return myXhr;
},
// Ajax events
beforeSend: function() {},
success: function (data) {},
error: function (err) {},
// Form data
data: formData,
// Options to tell jQuery not to process data or worry about content-type
cache: false,
contentType: false,
processData: false
});