(function ($) {
 $.extend($, {
 fileUpload: function (options) {
 var para = {
 multiple: true,
 filebutton: ".filePicker",
 uploadButton: null,
 url: "/home/MUploadImg",
 filebase: "mfile",//mvc后台需要对应的名称
 auto: true,
 previewZoom: null,
 uploadComplete: function (res) {
  console.log("uploadComplete", res);
 },
 uploadError: function (err) {
  console.log("uploadError", err);
 },
 onProgress: function (percent) { // 提供给外部获取单个文件的上传进度，供外部实现上传进度效果
  console.log(percent);
 },
 };
 para = $.extend(para, options);

 var $self = $(para.filebutton);
 //先加入一个file元素
 var multiple = ""; // 设置多选的参数
 para.multiple "multiple" : multiple = "";
 $self.css('position', 'relative');
 $self.append('<input id="fileImage" style="opacity:0;position:absolute;top: 0;left: 0;width:100%;height:100%" type="file" size="30" name="fileselect[]" ' + multiple + '>');

var doms = {
 "fileToUpload": $self.parent().find("#fileImage"),
 // "thumb": $self.find(".thumb"),
 // "progress": $self.find(".upload-progress")
 };
 var core = {
 fileSelected: function () {
  var files = (doms.fileToUpload)[0].files;
  var count = files.length;
  console.log("共有" + count + "个文件");
  for (var i = 0; i < count; i++) {
  var item = files[i];
  console.log(item.size);
  if (para.auto) {
  core.uploadFile(item);
  }
  core.previewImage(item);
  }
 },

 uploadFile: function (file) {
  console.log("开始上传");
  var formdata = new FormData();

  formdata.append(para.filebase, file);//这个名字要和mvc后台配合

  var xhr = new XMLHttpRequest();
  xhr.upload.addEventListener("progress", function (e) {

  var percentComplete = Math.round(e.loaded * 100 / e.total);
  para.onProgress(percentComplete.toString() + '%');
  });
  xhr.addEventListener("load", function (e) {
  para.uploadComplete(xhr.responseText);
  });
  xhr.addEventListener("error", function (e) {
  para.uploadError(e);
  });

  xhr.open("post", para.url, true);
  //xhr.setRequestHeader("X_FILENAME", file.name);
  xhr.send(formdata);
 },
 uploadFiles: function () {
  var files = (doms.fileToUpload)[0].files;
  for (var i = 0; i < files.length; i++) {
  core.uploadFile(files[i]);
  }
 },
 previewImage: function (file) {
  if (!para.previewZoom) return;
  var img = document.createElement("img");
  img.file = file;
  $(para.previewZoom).append(img);
  // 使用FileReader方法显示图片内容
  var reader = new FileReader();
  reader.onload = (function (aImg) {
  return function (e) {
  aImg.src = e.target.result;
  };
  })(img);
  reader.readAsDataURL(file);
 }
 }
 doms.fileToUpload.on("change", function () {
 //doms.progress.find("span").width("0");
 console.log("选中了文件");
 core.fileSelected();
 });

 console.log("初始化!");
 //绑定事件

 $(document).on("click", para.filebutton, function () {
 console.log("clicked");
 //doms.fileToUpload.click();
 });
 if (para.uploadButton) {
 $(document).on("click", para.uploadButton, function () {
  core.uploadFiles();
 });
 }
 }
 });
})(Zepto);

 [HttpPost]
 public ActionResult MUploadImg(HttpPostedFileBase mfile)
 {
 return UploadImg(mfile, "Mobile");
 }

 [HttpPost]
 public ActionResult UploadImg(HttpPostedFileBase file, string dir = "UserImg")
 {
 if (CheckImg(file, imgtypes) != "ok") return Json(new { Success = false, Message = "文件格式不对！" }, JsonRequestBehavior.AllowGet);

 if (file != null)
 {
 var path = "~/Content/UploadFiles/" + dir + "/";
 var uploadpath = Server.MapPath(path);
 if (!Directory.Exists(uploadpath))
 {
  Directory.CreateDirectory(uploadpath);
 }
 string fileName = Path.GetFileName(file.FileName);// 原始文件名称
 string fileExtension = Path.GetExtension(fileName); // 文件扩展名
 //string saveName = Guid.NewGuid() + fileExtension; // 保存文件名称 这是个好方法。
 string saveName = Encrypt.GenerateOrderNumber() + fileExtension; // 保存文件名称 这是个好方法。
 file.SaveAs(uploadpath + saveName);

 return Json(new { Success = true, SaveName = path + saveName });
 }
 return Json(new { Success = false, Message = "请选择要上传的文件！" }, JsonRequestBehavior.AllowGet);

 }

<div class="page" id="upload">
 <h2>UploadImg</h2>
 <div id="dd" class="filePicker">点击选择文件</div>
 <div id="preview"></div>
</div>
<script>
 $.fileUpload({ filebutton: "#dd", previewZoom: "#preview" });
</script>