//保存
function btnAdd() {
 var formData = new FormData($("#frm")[0]);

 $.ajax({
  url: "/Admin/ContentManage/SaveEdit",
  type: "POST",
  data: formData,
  contentType: false, //必须false才会避开jQuery对 formdata 的默认处理 XMLHttpRequest会对 formdata 进行正确的处理 
  processData: false, //必须false才会自动加上正确的Content-Type
  success: function (data) {
   if (data == "OK") {
    alert("保存成功");
    $.iDialog("close"); //刷新父页面
   }
   else {
    alert("保存失败：" + data);
   }
  }
 });
}

//首先判断路径是否存在,不存在则创建路径
string path = Path.Combine(System.Configuration.ConfigurationManager.AppSettings["UploadsFiles"], folder + "/" + DateTime.Now.ToString("yyyyMMdd") + "/");
string physicalPath = server.MapPath(path);
if (!Directory.Exists(physicalPath))
{
 Directory.CreateDirectory(physicalPath);
}

HttpPostedFileBase file = request.Files[0];
string newFileName = Guid.NewGuid().ToString().Replace("-", "") + Path.GetExtension(file.FileName);
string savePath = Path.Combine(physicalPath, newFileName);
file.SaveAs(savePath);
fileName = file.FileName;
string url = Path.Combine(path, newFileName);
return url;