通过DI在运行时注册服务？

Question

我正在使用ASP.NET Core并希望在运行时向IServiceProvider添加服务,因此可以通过DI在整个应用程序中使用它.

例如,一个简单的例子是用户进入设置控制器并将认证设置从"开"更改为"关".在那个例子中,我想替换在运行时注册的服务.

设置控制器中的Psuedo代码:

if(settings.Authentication == false)
{
     services.Remove(ServiceDescriptor.Transient<IAuthenticationService, AuthenticationService>());
     services.Add(ServiceDescriptor.Transient<IAuthenticationService, NoAuthService>());
}
else
{
     services.Remove(ServiceDescriptor.Transient<IAuthenticationService, NoAuthService>
     services.Add(ServiceDescriptor.Transient<IAuthenticationService, AuthenticationService>());
}

当我在Startup.cs中执行此操作时,此逻辑工作正常,因为IServiceCollection尚未构建到IServiceProvider中.但是,我希望能够在启动已经执行之后执行此操作.有谁知道这是否可能？

Answer 1

我不是在运行时注册/删除服务,而是创建一个服务工厂,它在运行时决定正确的服务.

services.AddTransient<AuthenticationService>();
services.AddTransient<NoAuthService>();
services.AddTransient<IAuthenticationServiceFactory, AuthenticationServiceFactory>();

AuthenticationServiceFactory.cs

public class AuthenticationServiceFactory: IAuthenticationServiceFactory
{
     private readonly AuthenticationService _authenticationService;
     private readonly NoAuthService_noAuthService;
     public AuthenticationServiceFactory(AuthenticationService authenticationService, NoAuthService noAuthService)
     {
         _noAuthService = noAuthService;
         _authenticationService = authenticationService;
     }
     public IAuthenticationService GetAuthenticationService()
     {
          if(settings.Authentication == false)
          {
             return _noAuthService;
          }
          else
          {
              return _authenticationService;
          }
     }
}

在课堂上使用:

public class SomeClass
{
    public SomeClass(IAuthenticationServiceFactory _authenticationServiceFactory)
    {
        var authenticationService = _authenticationServiceFactory.GetAuthenticationService();
    }
}