<script src="~/Scripts/MyAjaxForm.js"></script>

 @using (Ajax.BeginForm("AjaxAddUserPrintReport", "Admin", new AjaxOptions() { HttpMethod = "post", LoadingElementId = "loading", OnSuccess = "afterOk",OnFailure="afterErr" }, new { id = "addform", @class = "form-horizontal", enctype = "multipart/form-data" }))
    {

<div class="form-group">

            <label for="uploadfile" class="col-md-2 control-label">  上传文件：</label>

            <div class="col-md-4">

                <textarea class="form-control hidden" id="Uploadfileurl" name="Uploadfileurl" rows=""></textarea>

                <input type="file" id="fileup" name="fileup" />

                <button type="button" id="btnupload" class="btn btn-warning btn-sm">上传</button>

            </div>

            <div id="showfile" class="col-md-4">

            </div>

        </div>
}

  //点击上传文件

        $("#btnupload").click(function () {

            if ($(":file").val() == "")

            {

                alert("请选择上传文件后再点击上传按钮");

                return;

            }

            $("#addform").ajaxSubmit({

                error: function (error) { alert(error); },

                url: '/Admin/AjaxUploadFile',

                type: "post",

                success: function (data) {

                    var arr = data.split(":");

                    if (arr[] == "ok") {

                        $("#Uploadfileurl").val($("#Uploadfileurl").val().trim()==""?arr[]: $("#Uploadfileurl").val()+ "," + arr[]);

                        addfile();

                    }

                    else {

                        alert(arr[]);

                    }

                }

            });

        });

 /// <summary>
        /// 上传文件，最大上传10M
        /// </summary>
        /// <returns></returns> 

public ActionResult AjaxUploadFile()

        {

            try

            {

                HttpPostedFileBase uploadfile = Request.Files["fileup"];

                if (uploadfile == null)

                {

                    return Content("no:非法上传");

                }

                if (uploadfile.FileName == "")

                {

                    return Content("no:请选择文件");

                }

                if (uploadfile.ContentLength >  *  * )

                {

                    return Content("no:上传文件超过10M，实际上传大小为" + uploadfile.ContentLength);

                }

                string filename = Path.GetFileName(uploadfile.FileName);

                string fileExt = Path.GetExtension(filename);

                StringBuilder sbtime = new StringBuilder();

                sbtime.Append(DateTime.Now.Year).Append(DateTime.Now.Month).Append(DateTime.Now.Day).Append(DateTime.Now.Hour).Append(DateTime.Now.Minute).Append(DateTime.Now.Second);

                string dir = "/UploadFile/" + getUserBySession().Name + "/"  + filename.Substring(, filename.LastIndexOf(".")) + "_" + sbtime.ToString() + fileExt;

                string realfilepath = Request.MapPath(dir);

                string readDir = Path.GetDirectoryName(realfilepath);

                if (!Directory.Exists(readDir))

                    Directory.CreateDirectory(readDir);

                uploadfile.SaveAs(realfilepath);

                return Content("ok:" + dir);

            }

            catch (Exception ex)

            {

                return Content("no:" + ex.Message);

            }