C# DataTable 过滤、求和、去重

最近用DataTable用得的确有点多，开始的想法是用Linq对datatable进行 处理，进行一下总结：

1.只显示datatable其中需要的几列字段

            DataTable yl_dt = new DataTable();
            DataColumn dc0 = new DataColumn("卡号");
            DataColumn dc1 = new DataColumn("空");                     
            yl_dt.(dc0);
            yl_dt.(dc1);       
   

中某个字段的求和

1. 列为数字类型
double total= (("SUM(需要求和的参数)", ""));
 
2.列为string 类型  先转为数字类型 再求和
 
double total= ().Select(d => (<string>("amount"))).Sum();        
 

根据条件进行查询

        /// <summary>
        ///  dataTable根据条件查询
        /// </summary>
        /// <param name="dt">数据源</param>
        /// <param name="name">查询字段</param>
        /// <param name="value">查询条件值</param>
        /// <returns></returns>
        public DataTable ConditionQuery(DataTable dt, string name, string value)
        {
            //根据条件查询
            DataRow[] dr = (name + " = '" + value + "'");
            DataTable dt1 = ();
            for (int i = 0; i < ; i++)
            {
                (dr[i]);
            }
            return dt1;
        }

        /// <summary>
        ///  dataTable过滤筛选条件
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="name"></param>
        /// <param name="value"></param>
        public DataTable ConditionQuery(DataTable dt, string name, string value)
        {          

            ​​​​​​​DataView dataview = new DataView(dt);
             = $"{name} like'%{value}%'";
            return GetDataTable(dataview);
        }

        /// <summary>
        /// 将DataView转化为DataTable
        /// </summary>
        /// <param name="obDataView"></param>
        /// <returns></returns>
        public DataTable GetDataTable(DataView obDataView)
        {
            DataTable obNewDt = ();
            int idx = 0;
            string[] strColNames = new string[];
            foreach (DataColumn col in )
            {
                strColNames[idx++] = ;
            }

            IEnumerator viewEnumerator = ();
            while (())
            {
                DataRowView drv = (DataRowView);
                DataRow dr = ();
                try
                {
                    foreach (string strName in strColNames)
                    {
                        dr[strName] = drv[strName];
                    }
                }
                catch (Exception ex)
                {
                    ();
                }
                (dr);
            }
            return obNewDt;
        }

4.清除datatable中数据某字段相同的数据

         /// <summary>
        /// 清除重复字段
        /// </summary>
        /// <param name="dt">数据源</param>
        /// <param name="name">字段名</param>
        /// <returns></returns>
        public DataTable RefundDataExit(DataTable dt, string name)
        {
            for (int i = 0; i < ; i++)
            {
                string dr = [i][name].ToString();
                for (int j = i + 1; j < ; j++)
                {
                    string dr1 = [j][name].ToString();
                    if (dr == dr1)
                    {
                        (i);
                        (j - 1);
                        if (i == 0)
                        {
                            i = -1;
                        }
                    }
                }
            }
            return dt;
        }

如果大家有更好的方法，或者对datatable操作有其他的方法，欢迎指教