C# 拓展方法

  /// <summary>
     /// 扩展类
     /// </summary>
     public static class Extend
     {
         /// <summary>
         /// 扩展Join方法
         /// 把数组分割
         /// 截取最后一位
         /// </summary>
         /// <param name="s"></param>
         /// <param name="separotor">间隔符号</param>
         /// <param name="value">数组</param>
         /// <returns></returns>
         public static string E_Join(this string [] value,string separotor)
         {
             string str = string.Join(separotor, value);
             if (str.Length >= )
             {
                 return str.Substring(, str.Length - );
             }
             else
             {
                 return str;
             }
         }
     }