datatable 导出excel数据格式问题

Question

将datatable 导出excel之后有些数据变成了日期类型  很奇怪啊？

Answer 1

 #region 普通的Excel导出    /// <summary>    /// DataTable To Excel    /// </summary>    /// <param name="dt">DataTable Name</param>    /// <param name="typeid">1，Excel 2，XML</param>    /// <param name="FileName">文件名</param>    public void CreateExcel(System.Data.DataTable dt, string typeid, string FileName)
    {        HttpResponse resp;        resp = Page.Response;        resp.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");        resp.ContentType = "application/ms-excel";        resp.AddHeader("Content-Disposition","attachment; filename=" + System.Web.HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8) + ".xls");        this.EnableViewState = false;        string colHeaders = "", Is_item = "";        int i = 0;        //定义表对象与行对象，同时使用DataSet对其值进行初始化        DataRow[] myRow = dt.Select("");        //typeid=="1"时导出为Excel格式文件;typeid=="2"时导出为XML文件        if (typeid == "1")
        {            //取得数据表各列标题，标题之间以\t分割，最后一个列标题后加回车符            for (i = 0; i < dt.Columns.Count; i++)
            {                colHeaders += dt.Columns[i].Caption.ToString() + "\t";            }            colHeaders += "\n";            resp.Write(colHeaders);            //逐行处理数据            foreach (DataRow row in myRow)
            {                //在当前行中，逐列取得数据，数据之间以\t分割，结束时加回车符\n                for (i = 0; i < dt.Columns.Count; i++)
                {                    Is_item += row[i].ToString() + "\t";                }                Is_item += "\n";                resp.Write(Is_item);                Is_item = "";            }        }        else
        {            if (typeid == "2")
            {                //从DataSet中直接导出XML数据并且写到HTTP输出流中                resp.Write(dt.DataSet.GetXml());            }
        }
        //写缓冲区中的数据到HTTP头文件中
        resp.End();
    }    #endregion
    void OutPut(DataTable dt)
    {
        GridView gv = new GridView();
        gv.DataSource = dt;
        gv.DataBind();
        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "GB2312";
        Response.AppendHeader("Content-Disposition", "attachment;filename=FileName.xls");
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文
        Response.ContentType = "application/ms-excel";//设置输出文件类型为excel文件。 
        this.EnableViewState = false;
        System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("ZH-CN", true);
        System.IO.StringWriter oStringWriter = new System.IO.StringWriter(myCItrad);
        System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
        gv.RenderControl(oHtmlTextWriter);
        //this.DataGrid1.RenderControl(oHtmlTextWriter);
        Response.Write(oStringWriter.ToString());
        Response.End();
    }这里2中方法都得到一样的结果