/// <summary>
    /// DataTable中的数据导出到Excel并下载
    /// </summary>
    /// <param name="dt">要导出的DataTable</param>
    /// <param name="FileType">类型</param>
    /// <param name="FileName">Excel的文件名</param>
    public void CreateExcel(DataTable dt, string FileType, string FileName)
    {
        Response.Clear();
        Response.Charset = "UTF-8";
        Response.Buffer = true;
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
        Response.AppendHeader("Content-Disposition", "attachment;filename=\"" + System.Web.HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8) + ".xls\"");
        Response.ContentType = FileType;

        string colHeaders = string.Empty;
        string ls_item = string.Empty;
        DataRow[] myRow = dt.Select();
        int i = 0;
        int cl = dt.Columns.Count;
        
        //写入方法一
        //写入标题等信息
        ls_item +=  Label2.Text  + "\t\t\t\n\n";
        Response.Output.Write(ls_item);
        ls_item = string.Empty;
        ls_item +=  txtStart.Text + "\t\t\t";
        ls_item +=  DropEnterprise.SelectedItem  + "\n";
        Response.Output.Write(ls_item);
        ls_item = string.Empty;
        //写入段标题
        for (i = 0; i < cl; i++)
        {
            if (i == (cl - 1))
            {
                ls_item += dt.Columns[i].ColumnName.ToString() + "\n";
            }
            else
            {
                ls_item += dt.Columns[i].ColumnName.ToString() + "\t";
            }
        }
        Response.Output.Write(ls_item);
        ls_item = string.Empty;

        foreach (DataRow row in myRow)
        {
            for (i = 0; i < cl; i++)
            {
                if (i == (cl - 1))
                {
                    ls_item += row[i].ToString() + "\n";
                }
                else
                {
                    ls_item += row[i].ToString() + "\t";
                }
            }
            //一行一行的写入
            Response.Output.Write(ls_item);
            ls_item = string.Empty;
        }

        Response.Output.Flush();
        Response.End();
    }