asp.net上传execl文件后,在页面上加载显示(示例代码)

                    ViewState.Add("ViewDT", dt1);
                    GridView1.DataSource = ViewState["ViewDT"] as DataTable;
                    GridView1.DataBind();
                    file.Close();
                    //Maticsoft.Common.MessageBox.ResponseScript(Page, "$.messager.alert('系统提示', '操作成功！', 'info');");
                }
                catch
                {
                    Maticsoft.Common.MessageBox.ResponseScript(Page, "$.messager.alert('系统提示', '请重新上传Execl文件再操作', 'warning');");
                }
            }
            else
            {
                Label1.Text = "×文件上传失败";
            }
        }
        else
        {
            Label1.Text = "×请先选择上传文件";
        }
        ScriptManager.RegisterClientScriptBlock(Page, this.GetType(), "idAlert1", "closeLoad();", true);
    }
    #endregion

    #region 上传文件
    /// <summary>
    /// 上传文件
    /// </summary>
    /// <param name="fu">上传文件</param>
    /// <param name="type">上传文件类型,例如.jpg|.gif|.bmp</param>
    /// <param name="size">限制上传文件大小，单位为k</param>
    /// <param name="path">上传路径，需使用server.mappath</param>
    /// <param name="nametype">1为自动命名,0用原名</param>
    /// <returns></returns>
    public static string UpLoadFile(FileUpload fu, string type, int size, string path, int nametype, out string newFileName)
    {
        newFileName = null;
        string erorr = null;
        int Size = fu.PostedFile.ContentLength / 1024;
        if (Size > size)
        {
            erorr = "上传文件太大！";
            return erorr;
        }
        string Type = fu.FileName;
        if (Type.IndexOf(".") == -1) { erorr = "上传文件类型有误！"; return erorr; }
        Type = Type.Substring(Type.LastIndexOf(".")).ToUpper();
        type = type.ToUpper();
        if (type.IndexOf(Type) == -1) { erorr = "上传文件类型有误！"; return erorr; }

        string filename = "";
        if (nametype == 1)
        {
            string nowdate = DateTime.Now.ToString();
            nowdate = nowdate.Replace(":", "").Replace(" ", "").Replace("-", "").Trim();
            Random r = new Random();
            int a = r.Next(1000);
            filename = nowdate + a.ToString() + Type;
            newFileName = filename;
        }
        else
        {
            filename = fu.FileName;
            if (System.IO.File.Exists(path + filename)) { erorr = "此文件名已经存在！"; return erorr; }
        }

        fu.SaveAs(path + filename);