public interface ITimeProvider
    {
        DateTime CurrentDate { get; }
    }
    public class TimeProvider : ITimeProvider
    {
        public DateTime CurrentDate { get { return DateTime.Now; } }
    }
   
    //下面实现这个Assembler
    public class Assembler
    {
        static Dictionary<Type, Type> dictionary = new Dictionary<Type, Type>();
        static Assembler()
        {
            dictionary.Add(typeof(ITimeProvider), typeof(TimeProvider));
        }

        public object Creat(Type type)
        {
            if ((type == null) || !dictionary.ContainsKey(type))
                throw new NullReferenceException();
            return Activator.CreateInstance(dictionary[type]);
        }

        //泛型方式调用
        public T Creat<T>()
        {
            return (T)Creat(typeof(T));
        }
    }

    //public class Client : IobjectWithTimeProvider
    //{
    //    public ITimeProvider TimeProvider { get; set; }
    //}
    //通过泛型参数实现接口注入 Client设计
    class Client<T> : ITimeProvider where T : ITimeProvider
    {
        public T Provider { get; set; }
        public DateTime CurrentDate
        {
            get { return Provider.CurrentDate; }
        }
    }

 

 

测试

 

 /// <summary>
    ///这是 ClientTest 的测试类,旨在
    ///包含所有 ClientTest 单元测试
    ///</summary>
    [TestClass()]
    public class ClientTest
    {


      

        [TestMethod()]
        public void CurrentDateTest()
        {
            var client = new Client<ITimeProvider>()
            {
                Provider = (new Assembler()).Creat<ITimeProvider>()
            };

        }
    }