在Startup类中获取依赖DI的类的实例

public class Startup
{
    private readonly IServiceProvider _serviceProvider;

    public Startup(IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }

    // 其他Startup类的代码...
}

public class SomeClass
{
    private readonly IDependency _dependency;

    public SomeClass(IServiceProvider serviceProvider)
    {
        _dependency = serviceProvider.GetService<IDependency>();
    }

    // 其他SomeClass类的代码...
}

public void ConfigureServices(IServiceCollection services)
{
    services.AddTransient<IDependency, DependencyImplementation>();

    // 其他服务的注册...
}