mvcfile控件无刷新异步上传操作源码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Web;
namespace CommonHelper
{
 public class UploadFile : System.Web.UI.Page
 {
  public UploadFile()
  {

  }
  //错误信息
  public string msg { get; set; }
  public string FullName { get; set; }
  //文件名称
  public string FileName { get; set; }
  /// 

  /// 文件上传
  /// by wyl 20161019
  /// 
  /// 文件上传地址
  /// 文件规定大小
  /// 文件类型
  /// file上传的文件
  /// 是否重名名
  /// 
  public bool upload_file(string filepath, int size, string[] filetype, bool isrename = false)
  {
   filepath = Server.MapPath(filepath);
   //文件夹不存在就创建
   if (!Directory.Exists(filepath))
    Directory.CreateDirectory(filepath);
   if (HttpContext.Current.Request.Files.Count == 0)
   {
    msg = "文件上传失败";
    return false;
   }
   msg = "上传成功";
   var file = HttpContext.Current.Request.Files[0];
   if (file.COntentLength== 0)
   {
    msg = "文件大小为0";
    return false;
   }
   if (file.ContentLength > size * 1024)
   {
    msg = "文件超出指定大小";
    return false;
   }
   var filex = HttpContext.Current.Request.Files[0];
   string fileExt = Path.GetExtension(filex.FileName).ToLower();
   if (filetype.Count(a => a == fileExt) <1)
   {
    msg = "文件类型不支持";
    return false;
   }
   if (isrename)
    FileName = DateTime.Now.ToString("yyyyMMddHHmmss") + fileExt;
   FileName = filex.FileName;
   FullName = Path.Combine(filepath, FileName);
   file.SaveAs(FullName);
   return true;
  }
 }
}

 [HttpPost]
  public ActionResult FileUpload()
  {
   //从配置文件中获取支持上传文件格式
   string[] fileType = ConfigurationManager.AppSettings["fileType"].Split('|');
   //上传文件路径
   string strPath = ConfigurationManager.AppSettings["strPath"];
   UploadFile file= new UploadFile();
   bool flag = file.upload_file(strPath, 25000, fileType);
   return Content("");
  }