自定義IOC

為什么不直接用Core自帶的IOC?
1. 能夠理解本質(zhì)
2. 擴(kuò)展性更強(qiáng)

接上一章擴(kuò)展 ： 《.Net Core 3.x MVC DIP與Factory》

這章完成目標(biāo)：
1.多參數(shù)
2.多構(gòu)造函數(shù)（參數(shù)數(shù)量/特性標(biāo)識(shí)）

開始擼碼

在 AspNetCore.IOCDI.Framework 添加 容器接口 和 容器實(shí)現(xiàn)類

容器實(shí)現(xiàn) 躯肌，這里容器實(shí)現(xiàn)了無限級(jí)遞歸春宣，和 特性標(biāo)記

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

namespace AspNetCore.IOCDI.Framework.CustomContainer
{
    /// <summary>
    /// 用來生產(chǎn)對(duì)象
    /// 第三方   業(yè)務(wù)無關(guān)性
    /// </summary>
    public class CoreContainer: ICoreContainer
    {
        private Dictionary<string, Type> CoreContainerDictionary = new Dictionary<string, Type>();

        /// <summary>
        /// where TTo 必須是 TFrom 類型的約束
        /// </summary>
        public void Register<TFrom, TTo>() where TTo: TFrom
        {
            //用TFrom的名稱作為Key ,用 TTo 這個(gè)類型作為Value
            this.CoreContainerDictionary.Add(typeof(TFrom).FullName,typeof(TTo));
        }

        /// <summary>
        /// 用類型名稱找出類型澜建，返回 創(chuàng)建好的對(duì)象
        /// </summary>
        /// <typeparam name="TFrom"></typeparam>
        /// <returns></returns>
        public TFrom Resolve<TFrom>() {
            return (TFrom)this.ResolveObject(typeof(TFrom));
        }

        /// <summary>
        /// 遞歸--可以完成不限層級(jí)的東西
        /// </summary>
        private object ResolveObject(Type abstracttype)
        {
            string key = abstracttype.FullName;

            Type type = this.CoreContainerDictionary[key];

            #region 選擇適合的構(gòu)造函數(shù)

            ConstructorInfo ctor = null;
            
            //是否有標(biāo)記，有特性標(biāo)記用特性標(biāo)記剑令，沒有就用參數(shù)最多的
            ctor = type.GetConstructors().FirstOrDefault(c => c.IsDefined(typeof(CoreConstructorAttribute), true));
            if (ctor == null)
            {
                //找參數(shù)最多的
                ctor = type.GetConstructors().OrderByDescending(c => c.GetParameters().Length).First();
            }
            
            #endregion


            #region 準(zhǔn)備構(gòu)造函數(shù)的參數(shù)

            List<object> paraList = new List<object>();

            foreach (var para in ctor.GetParameters())
            {
                Type paraType = para.ParameterType;//獲取參數(shù)的類型 IUserDAL
                
                object paraInstance = this.ResolveObject(paraType);
                
                paraList.Add(paraInstance);
            }

            #endregion

            object oInstance = Activator.CreateInstance(type, paraList.ToArray());

            return oInstance;
        }
    }
}

TestServiceA 實(shí)現(xiàn)

using AspNetCore.IOCDI.Interface;
using System;

namespace AspNetCore.IOCDI.Service
{
    public class TestServiceA : ITestServiceA
    {
        public TestServiceA() {
            Console.WriteLine($"{ this.GetType().Name }被構(gòu)造拄查。吁津。。");
        }

        public void Show()
        {
            Console.WriteLine("這里是 TestServiceA Show.");
        }
    }
}

TestServiceB 實(shí)現(xiàn)

using AspNetCore.IOCDI.Interface;
using System;

namespace AspNetCore.IOCDI.Service
{
    public class TestServiceB : ITestServiceB
    {
        
        public TestServiceB(ITestServiceA iTestServiceA) {
            Console.WriteLine($"{ this.GetType().Name }被構(gòu)造堕扶。碍脏。。");
        }

        private ITestServiceA _iTestServiceA = null;

        public void Init(ITestServiceA testServiceA) {
            this._iTestServiceA = testServiceA;
        }

        public void Show()
        {
            Console.WriteLine("這里是 TestServiceB Show.");
        }
    }
}