net6内置IOC容器使用

1、创建控制台应用程序

2、Nuget引用Microsoft.Extensions.DependencyInjection

3、创建Business.IServices类库

创建接口IPower、IMicrophone.cs、IHeadphone

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Business.IServices
{
    public interface IPower
    {
    }
}

namespace Business.IServices
{
    public interface IMicrophone
    {
       
    }
}

namespace Business.IServices
{
    public  interface IHeadphone
    {
    }
}

 

4、创建Business.Services类库

创建类Power继承 IPower，Microphone继承IMicrophone，Headphone继承

using Business.IServices;

namespace Business.Services
{
    public class Power :IPower
    {
        public Power(IMicrophone microphone)
        {
            Console.WriteLine($"{this.GetType().Name}被构造了");
        }
    }
}

using Business.IServices;

namespace Business.Services
{
    public class Microphone : IMicrophone
    {
        public Microphone()
        {
            Console.WriteLine($"{this.GetType().Name}被构造..");
        }
    }
}

using Business.IServices;

namespace Business.Services
{
    public class Headphone : IHeadphone
    {
        public Headphone(IPower power)
        {
            Console.WriteLine($"{this.GetType().Name}被构造...");
        }
    }
}

5、修改Program.cs

using Business.IServices;
using Business.Services;
using Microsoft.Extensions.DependencyInjection;

{
    //1、创建容器
    ServiceCollection serviceDescriptors = new ServiceCollection();
    //2、注册抽象和具体普通类之间的关系
    serviceDescriptors.AddTransient<IPower, Power>();
    serviceDescriptors.AddTransient<IMicrophone, Microphone>();
    serviceDescriptors.AddTransient<IHeadphone, Headphone>();
    //3、serviceDescriptions.builder
    ServiceProvider serviceProvider = serviceDescriptors.BuildServiceProvider();

   //创建实例
    IHeadphone headphone = serviceProvider.GetService<IHeadphone>();
}

 

6、文件结构

 

 

7、启动调试

可以发现程序会依次执行Microphone、Power、Headphone的构造函数，然后创建Headphone实例

这是控制反转的构造函数注入，但一个实例需要被创建时，它的构造函数需要的参数实例会一层层追溯，然后创建构造函数参数需要的实例。