/// <summary>
 /// 获得指定列查重后组成的字符串[[用“,”做为分隔符],按指定长度分组
 /// </summary>
 /// <param name="dt"></param>
 /// <param name="ColumnName"></param>
 /// <param name="MaxLength"></param>
 /// <returns></returns>
 public static IEnumerable <string> FormatGroupStrValue(this DataTable dt, string ColumnName, int MaxLength)
 {
     return(CommonFormatStrTools.GetDataTableColValueFormatGroupStr(dt, ColumnName, ",", MaxLength));
 }