按名称解析的依赖注入 [英] Dependency injection resolving by name

问题描述

如何为特定类注入不同的对象实现?

How can I inject different implementation of object for a specific class?

比如在Unity中，我可以定义两个IRepository

For example, in Unity, I can define two implementations of IRepository

container.RegisterType<IRepository, TestSuiteRepositor("TestSuiteRepository");
container.RegisterType<IRepository, BaseRepository>(); 

并调用所需的实现

public BaselineManager([Dependency("TestSuiteRepository")]IRepository repository)

推荐答案

正如@Tseng 所指出的，命名绑定没有内置解决方案.但是，使用工厂方法可能对您的情况有所帮助.示例应如下所示:

As @Tseng pointed, there is no built-in solution for named binding. However using factory method may be helpful for your case. Example should be something like below:

创建存储库解析器:

public interface IRepositoryResolver
{
    IRepository GetRepositoryByName(string name);
}

public class RepositoryResolver : IRepositoryResolver 
{
    private readonly IServiceProvider _serviceProvider;
    public RepositoryResolver(IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }
    public IRepository GetRepositoryByName(string name)
    {
         if(name == "TestSuiteRepository") 
           return _serviceProvider.GetService<TestSuiteRepositor>();
         //... other condition
         else
           return _serviceProvider.GetService<BaseRepositor>();
    }

}

在ConfigureServices.cs

services.AddSingleton<IRepositoryResolver, RepositoryResolver>();
services.AddTransient<TestSuiteRepository>();
services.AddTransient<BaseRepository>(); 

最后在任何类中使用它:

Finally use it in any class:

public class BaselineManager
{
    private readonly IRepository _repository;

    public BaselineManager(IRepositoryResolver repositoryResolver)
    {
        _repository = repositoryResolver.GetRepositoryByName("TestSuiteRepository");
    }
}

这篇关于按名称解析的依赖注入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！