/// <summary>     /// 权限设置二进制     /// </summary>     [Flags]     public enum Permissions     {         Add = 1,         Del = 2,         Mod = 4,         Select = 8     }     /// <summary>     /// 判断是否拥有此权限，false=不存在，true=存在     /// </summary>     /// <param name="value">权限类型值</param>     /// <param name="per">操作类型：增删改查</param>     /// <returns>判断是否拥有此权限，false=不存在，true=存在</returns>     public static bool IsPermission(int value, Permissions per)     {         bool bo = false;//默认不存在         switch (per)         {             case Permissions.Add:                 if ((value & Convert.ToInt32(Permissions.Add)) == Convert.ToInt32(Permissions.Add))//运算  (value & 1)==1                     bo = true;                 break;             case Permissions.Del:                 if ((value & Convert.ToInt32(Permissions.Del)) == Convert.ToInt32(Permissions.Del))//                     bo = true;                 break;             case Permissions.Mod:                 if ((value & Convert.ToInt32(Permissions.Mod)) == Convert.ToInt32(Permissions.Mod))//                     bo = true;                 break;             case Permissions.Select:                 if ((value & Convert.ToInt32(Permissions.Select)) == Convert.ToInt32(Permissions.Select))//                     bo = true;                 break;         }         return bo;     }