在没有新的IServiceProvider实例的情况下指定自定义IModelBinderProvider？

我的类中有以下代码Startup，它使用IModelBinderProvider. 大多数输入格式化程序需要一个ILogger实例，所以我需要有一个ILoggerFactory，为此我想使用配置的一个，它以指定的详细程度记录到指定的目的地。我正在ILoggerFactory从一个新建的IServiceProvider：

    public void ConfigureServices(IServiceCollection services)
    {
        ...
    
        services.AddMvcCore(
            options =>
            {
                ...
            
                var serviceProvider = services.BuildServiceProvider();
                var loggerFactory = serviceProvider.GetService<ILoggerFactory>();

                options.ModelBinderProviders.Clear();
                options.ModelBinderProviders.Add(
                    new MyCustomBinderProvider(options.InputFormatters, loggerFactory)
                );
                
                ...
            }
        );
        
        ...
    }

问题是我收到以下警告：

Startup.cs(62, 43): [ASP0000] Calling 'BuildServiceProvider' from application code results in an
                    additional copy of singleton services being created. Consider alternatives such
                    as dependency injecting services as parameters to 'Configure'.

我看了一下这个问题：Resolving instances with ASP.NET Core DI from inside ConfigureServices。但是，我的代码是 的 lambda AddMvcCore，它正在配置options对象。换句话说，在Configure调用 时，MVC 选项已经定义。

有没有办法在这里做正确的事情，即防止无关的实例IServiceProvider？

回答

services.AddOptions<MvcOptions>()
         //first arg is always of TOptions, 
         //injectable dependencies start from the second arg
        .Configure((MvcOptions o, ILoggerFactory loggerFactory) => {
                       o.ModelBinderProviders.Insert(0,
                          new MyCustomBinderProvider(o.InputFormatters, loggerFactory)
                       );
                   });

public class ConfigureMvcOptions : IConfigureOptions<MvcOptions>
{
    readonly ILoggerFactory _loggerFactory;
    public ConfigureMvcOptions(ILoggerFactory loggerFactory)
    {
        _loggerFactory = loggerFactory;
    }
    public void Configure(MvcOptions options)
    {
        options.ModelBinderProviders.Insert(0,
                  new MyCustomBinderProvider(options.InputFormatters, _loggerFactory)
               );
    }
}

//then configure it like this:
services.ConfigureOptions<ConfigureMvcOptions>();