c#典型工厂化实现实例

工厂接口定义

        /// <summary>
        /// 如果需要同时加载配置文件中定义的映射关系，可以按照SRP的原则定义独立的配置类型。
        /// 由该配置类型调用这两个接口为Factory加载配置信息
        /// </summary>

        IFactory RegisterType<TTarget, TSource>();  // fluent interface
        IFactory RegisterType<TTarget, TSource>(string name);   // fluent interface

        #endregion

        #region factory method

        TTarget Create<TTarget>();
        TTarget Create<TTarget>(string name);

        #endregion
    }
</div>

注册类

            if (!registry.TryGetValue(targetType, out subDictionary))
            {
                subDictionary = new Dictionary<string, Type>();
                subDictionary.Add(name, sourceType);
                registry.Add(targetType, subDictionary);
            }
            else
            {
                if (subDictionary.ContainsKey(name))
                    throw new DuplicateKeyException(name);
                subDictionary.Add(name, sourceType);
            }
        }
        public Type this[Type targetType, string name]
        {
            get
            {
                if (targetType == null) throw new ArgumentNullException("targetType");
                if (string.IsNullOrEmpty(name)) throw new ArgumentNullException("name");
                if (registry.Count() == 0)
                    return null;

                return (registry
                    .Where(x => x.Key == targetType)).FirstOrDefault().Value
                    .Where(x => string.Equals(name, x.Key))
                        .FirstOrDefault().Value;
            }
        }

        public Type this[Type targetType]
        {
            get { return this[targetType, DefaultNmae]; }
        }

    }
</div>

工厂类

        #region IFactory Members

        public IFactory RegisterType<TTarget, TSource>()
        {
            registry.RegisterType(typeof(TTarget), typeof(TSource));
            return this;
        }

        public IFactory RegisterType<TTarget, TSource>(string name)
        {
            registry.RegisterType(typeof(TTarget), typeof(TSource), name);
            re