泛型实例

方法的定义：（方法的返回值和参数都是泛型）

 public static T[] GetAllDataBySort<T>(string sort) where T : NormalObj
        {
            return GetAllDataBySort<T>(sort, "");
        }

        public static T[] GetAllDataBySort<T>(string sort, string special) where T : NormalObj
        {
            string sql;
            if (!string.IsNullOrEmpty(special))
                sql = string.Format("select * from {0} where {1} order by {2}", typeof(T).Name, special, sort);
            else
                sql = string.Format("select * from {0} order by {1}", typeof(T).Name, sort);
            T[] obj = default(T[]);
            obj = Sql.select<T>(sql);
            if (obj != null)
                return obj;
            throw new Exception("异常");
        }

        /// <summary>
        /// 根据对象所限定条件获得一定的对象集合
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public T[] GetSomeObject<T>() where T : NormalObj, new()//new() 规定T必须带无参构造函数
        {
            return GetSomeObject<T>("");
        }

方法的调用：

public static DB.TravelObj.City[] GetCitiesByCompanyId(long CompanyId)
        {
            City obj = new City();
            obj.Cstate = 1;
            obj.CcompanyId = CompanyId;
            return obj.GetSomeObject<DB.TravelObj.City>();
        }