三、手写Unity容器--第N层依赖注入

这个场景跟《手写Unity容器--极致简陋版Unity容器》不一样，这里构造AndroidPhone的时候，AndroidPhone依赖于1个IPad

 

一、IPhone接口

namespace SimplestUnity_nLayer { interface IPhone { void Call(); } }

二、AndroidPhone实现

namespace SimplestUnity_nLayer { public class AndroidPhone : IPhone { public AndroidPhone(IPad iPad, IHeadPhone iHeadPhone) { Console.WriteLine("{0}构造函数", this.GetType().Name); } } }

三、IPad接口

namespace SimplestUnity_nLayer { public interface IPad { void Show(); } }

四、IPad实现

namespace SimplestUnity_nLayer { public class AndroidPad:IPad { public AndroidPad() { Console.WriteLine("{0}构造函数", this.GetType().Name); } public void Show() { Console.WriteLine("看{0}", this.GetType().Name); } } }

五、IHeadPhone接口

namespace SimplestUnity_nLayer { public interface IHeadPhone { } }

六、IHeadPhone实现

namespace SimplestUnity_nLayer { public class HeadPhone : IHeadPhone { public HeadPhone(IRootPhone iRootPhone) { Console.WriteLine("Headphone 被构造"); } } }

七、IRootPhone接口

namespace SimplestUnity_nLayer { public interface IRootPhone { } }

八、IRootPhone实现

namespace SimplestUnity_nLayer { public class RootPhone : IRootPhone { public RootPhone() { Console.WriteLine("RootPhone 被构造"); } } }

九、容器--接口

public interface IDavidContainer { void RegisterType<TFrom, TTo>(); T Resolve<T>(); }

十、容器--实现

namespace SimplestUnity_nLayer { /// <summary>
    /// 容器--工厂 /// </summary>
    public class DaivdContainer:IDaivdContainer { private Dictionary<string, Type> containerDictionary = new Dictionary<string, Type>();//字典

        /// <summary>
        /// 注册类型 /// </summary>
        /// <typeparam name="TFrom"></typeparam>
        /// <typeparam name="TTo"></typeparam>
        public void RegisterType<TFrom, TTo>() { containerDictionary.Add(typeof(TFrom).FullName, typeof(TTo)); } /// <summary>
        /// 获取实例 /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public T Resolve<T>() { Type type = containerDictionary[typeof(T).FullName]; return (T)this.CreateInstance(type); } private object CreateInstance(Type type) { //一、获得类型的全部构造函数
            ConstructorInfo[] ctorArray = type.GetConstructors(); //二、只获得有标记DavidInjectionConstructor特性的构造函数，若是都没有标记特性，那么获得参数最多的构造函数
            ConstructorInfo currentCtor = null; if (ctorArray.Count(c => c.IsDefined(typeof(DavidInjectionConstructor), true)) > 0) { currentCtor = ctorArray.FirstOrDefault(c => c.IsDefined(typeof(DavidInjectionConstructor), true));//获得第1个标记DavidInjectionConstructor特性的构造函数
 } else { currentCtor = ctorArray.OrderByDescending(c => c.GetParameters().Length).FirstOrDefault();//获得参数个数最多的构造函数
 } List<object> paraList = new List<object>(); //递归：隐形的跳出条件，条件就是GetParameters结果为空，targetType拥有无参数构造函数
            foreach (var para in currentCtor.GetParameters()) { //获得的参数类型是IPad，抽象没法建立实例
                var paraType = para.ParameterType; //因此根据IPad Key，获得AndroidPad类型，具体类型就能够建立实例
                var targetParaType = containerDictionary[paraType.FullName]; //继续检查targetParaType的构造函数，不能直接建立实例了
                Object obj = this.CreateInstance(targetParaType); paraList.Add(obj); } return Activator.CreateInstance(type, paraList.ToArray()); } } }

十一、调用

class Program { static void Main(string[] args) { DaivdContainer davidContainer = new DaivdContainer(); davidContainer.RegisterType<IPhone, AndroidPhone>(); davidContainer.RegisterType<IPad, AndroidPad>(); davidContainer.RegisterType<IHeadPhone, HeadPhone>(); davidContainer.RegisterType<IRootPhone, RootPhone>(); IPhone iphone = davidContainer.Resolve<IPhone>(); iphone.Call(); } }