C# DataTable导出Excel

//点击导出按钮  
 protected void btnExecl_Click(object sender, EventArgs e)
        {
           //绑定数据源
            DataSet ds = bll.GetList("Result=25");
            if (ds.Tables[0].Rows.Count > 0)
            {
                DataTable dt = new DataTable();
                dt.Columns.Add("RTime", typeof(System.String));
                dt.Columns.Add("Result", typeof(System.String));
                dt.Columns.Add("OName", typeof(System.String));
                dt.Columns.Add("OSex", typeof(System.String));
                dt.Columns.Add("OPhone", typeof(System.String));
                dt.Columns.Add("OXueLi", typeof(System.String));
                dt.Columns.Add("OAge", typeof(System.String));
                dt.Columns.Add("OAddress", typeof(System.String));
                for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                {
                    DataRow dr = dt.NewRow();
                    dr["RTime"] = ds.Tables[0].Rows[i]["RTime"].ToString();
                    dr["Result"] = ds.Tables[0].Rows[i]["Result"].ToString();
                    dr["OName"] = ds.Tables[0].Rows[i]["OName"].ToString();
                    dr["OSex"] = ds.Tables[0].Rows[i]["OSex"].ToString();
                    dr["OPhone"] = ds.Tables[0].Rows[i]["OPhone"].ToString();
                    dr["OXueLi"] = ds.Tables[0].Rows[i]["OXueLi"].ToString();
                    dr["OAge"] = ds.Tables[0].Rows[i]["OAge"].ToString();
                    dr["OAddress"] = ds.Tables[0].Rows[i]["OAddress"].ToString();
                    dt.Rows.Add(dr);
                }
                //调用导出
                ExportExcel(dt, "导出数据：全对答题名单", "全对答题名单");
            }
            else
            {
                ScriptManager.RegisterClientScriptBlock(UpdatePanel1, this.GetType(), "", "yz('没有数据，无法导出',1);", true);
                return;
            }
        }

        #region 导出数据
        /// <summary>
        /// DataTable导出Excel
        /// </summary>
        /// <param name="dt">datatable数据源</param>
        /// <param name="strFileName">文件名</param>
        /// <param name="strSheetName">工作簿名</param>
        public void ExportExcel(DataTable dt, string strFileName, string strSheetName)
        {
            HSSFWorkbook book = new HSSFWorkbook();
            ISheet sheet = book.CreateSheet(strSheetName);

            IRow headerrow = sheet.CreateRow(0);
            ICellStyle style = book.CreateCellStyle();
            style.Alignment = HorizontalAlignment.Center;
            style.VerticalAlignment = VerticalAlignment.Center;

            HSSFRow dataRow = (HSSFRow)sheet.CreateRow(0);
            string strColumns = "答题时间,答对,姓名,性别,手机,职业,年龄,区域";
            string[] strArry = strColumns.Split(',');
            for (int i = 0; i < strArry.Length; i++)
            {
                dataRow.CreateCell(i).SetCellValue(strArry[i]);
                dataRow.GetCell(i).CellStyle = style;
            }

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                dataRow = (HSSFRow)sheet.CreateRow(i + 1);
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    string ValueType = "";
                    string Value = "";
                    if (dt.Rows[i][j].ToString() != null)
                    {
                        ValueType = dt.Rows[i][j].GetType().ToString();
                        Value = dt.Rows[i][j].ToString();
                    }
                    switch (ValueType)
                    {
                        case "System.String"://字符串类型
                            dataRow.CreateCell(j).SetCellValue(Value);
                            break;
                        case "System.DateTime"://日期类型
                            System.DateTime dateV;
                            System.DateTime.TryParse(Value, out dateV);
                            dataRow.CreateCell(j).SetCellValue(dateV);
                            break;
                        case "System.Boolean"://布尔型
                            bool boolV = false;
                            bool.TryParse(Value, out boolV);
                            dataRow.CreateCell(j).SetCellValue(boolV);
                            break;
                        case "System.Int16"://整型
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            int intV = 0;
                            int.TryParse(Value, out intV);
                            dataRow.CreateCell(j).SetCellValue(intV);
                            break;
                        case "System.Decimal"://浮点型
                        case "System.Double":
                            double doubV = 0;
                            double.TryParse(Value, out doubV);
                            dataRow.CreateCell(j).SetCellValue(doubV);
                            break;
                        case "System.DBNull"://空值处理
                            dataRow.CreateCell(j).SetCellValue("");
                            break;
                        default:
                            dataRow.CreateCell(j).SetCellValue("");
                            break;
                    }
                    dataRow.GetCell(j).CellStyle = style;
                    //设置宽度
                    sheet.SetColumnWidth(j, (Value.Length + 10) * 256);
                }
            }

            MemoryStream ms = new MemoryStream();
            book.Write(ms);
            Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", HttpUtility.UrlEncode(strFileName, System.Text.Encoding.UTF8)));
            Response.BinaryWrite(ms.ToArray());
            Response.End();
            book = null;
            ms.Close();
            ms.Dispose();
        }
        #endregion