Winform中GridView分组排序功能实现方法

        private string MonthToString(int month)
        {
            if (month >= 1 && month <= 9)
                return "0" + month.ToString();
            else
                return month.ToString();
        }
    }
}
DBHelp类源码：
复制代码 using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
namespace GridViewSortTest
{
  public class DBHelp
    {
        //连接字符串
      static string strConn =@"Server=.SQLEXPRESS; Database= SysBusiness; User Id=sa; Password=123456;Trusted_Connection = False ";

 

        #region 执行查询，返回DataTable对象-----------------------

        public static DataTable GetTable(string strSQL)
        {
            return GetTable(strSQL, null);
        }
        public static DataTable GetTable(string strSQL, SqlParameter[] pas)
        {
            return GetTable(strSQL, pas, CommandType.Text);
        }
        /// <summary>
        /// 执行查询，返回DataTable对象
        /// </summary>
        /// <param name="strSQL">sql语句</param>
        /// <param name="pas">参数数组</param>
        /// <param name="cmdtype">Command类型</param>
        /// <returns>DataTable对象</returns>
        public static DataTable GetTable(string strSQL, SqlParameter[] pas, CommandType cmdtype)
        {