您可以避免使用静态类，并始终使用依赖注入，同时结合使用：

• 每当应用程序启动/停止时，使用IApplicationLifetime启动/停止侦听器。
• 使用IServiceProvider创建消息处理器的示例。

首先，让我们将配置移到它自己的类中，该类可以从appsettings.json中填充：

public class RabbitOptions
{
    public string HostName { get; set; }
    public string UserName { get; set; }
    public string Password { get; set; }
    public int Port { get; set; }
}

// In appsettings.json:
{
  "Rabbit": {
    "hostName": "192.168.99.100",
    "username": "guest",
    "password": "guest",
    "port": 5672
  }
}

接下来，将MessageHandlerFactory转换为一个非静态类，该类接收一个IServiceProvider作为依赖项，它将使用服务提供程序来解析消息处理器示例：

public class MessageHandlerFactory
{
    private readonly IServiceProvider services;
    public MessageHandlerFactory(IServiceProvider services)
    {
        this.services = services;
    }

    public IMessageProcessor Create(string messageType)
    {
        switch (messageType.ToLower())
        {
            case "ipset":
                return services.GetService<IpSetMessageProcessor>();                
            case "endpoint":
                return services.GetService<EndpointMessageProcessor>();
            default:
                throw new Exception("Unknown message type");
        }
    }
}

通过这种方式，消息处理器类可以在构造函数中接收它们需要的任何依赖项（只要在Startup.ConfigureServices中配置它们）。例如，我将一个ILogger注入到我的一个示例处理器中：

public class IpSetMessageProcessor : IMessageProcessor
{
    private ILogger<IpSetMessageProcessor> logger;
    public IpSetMessageProcessor(ILogger<IpSetMessageProcessor> logger)
    {
        this.logger = logger;
    }

    public void Process(string message)
    {
        logger.LogInformation("Received message: {0}", message);
    }
}

现在把MessageListener转换成一个依赖于IOptions<RabbitOptions>和MessageHandlerFactory的非静态类，它和你原来的类非常相似，我只是用选项依赖替换了Start方法的参数，处理器工厂现在是一个依赖而不是静态类：

public class MessageListener
{
    private readonly RabbitOptions opts;
    private readonly MessageHandlerFactory handlerFactory;
    private IConnection _connection;
    private IModel _channel;

    public MessageListener(IOptions<RabbitOptions> opts, MessageHandlerFactory handlerFactory)
    {
        this.opts = opts.Value;
        this.handlerFactory = handlerFactory;
    }

    public void Start()
    {
        var factory = new ConnectionFactory
        {
            HostName = opts.HostName,
            Port = opts.Port,
            UserName = opts.UserName,
            Password = opts.Password,
            VirtualHost = "/",
            AutomaticRecoveryEnabled = true,
            NetworkRecoveryInterval = TimeSpan.FromSeconds(15)
        };

        _connection = factory.CreateConnection();
        _channel = _connection.CreateModel();
        _channel.ExchangeDeclare(exchange: "myExchange", type: "direct", durable: true);

        var queueName = "myQueue";

        QueueDeclareOk ok = _channel.QueueDeclare(queueName, true, false, false, null);

        _channel.QueueBind(queue: queueName, exchange: "myExchange", routingKey: "myRoutingKey");

        var consumer = new EventingBasicConsumer(_channel);
        consumer.Received += ConsumerOnReceived;

        _channel.BasicConsume(queue: queueName, noAck: false, consumer: consumer);

    }

    public void Stop()
    {
        _channel.Close(200, "Goodbye");
        _connection.Close();
    }

    private void ConsumerOnReceived(object sender, BasicDeliverEventArgs ea)
    {
        // get the details from the event
        var body = ea.Body;
        var message = Encoding.UTF8.GetString(body);
        var messageType = "endpoint";  // hardcoding the message type while we dev...
        //var messageType = Encoding.UTF8.GetString(ea.BasicProperties.Headers["message-type"] as byte[]);

        // instantiate the appropriate handler based on the message type
        IMessageProcessor processor = handlerFactory.Create(messageType);
        processor.Process(message);

        // Ack the event on the queue
        IBasicConsumer consumer = (IBasicConsumer)sender;
        consumer.Model.BasicAck(ea.DeliveryTag, false);
    }
}

到了这里，您需要更新Startup.ConfigureServices方法，使它知道您的服务和选项（如果需要，可以为侦听器和处理程序工厂创建接口）：

public void ConfigureServices(IServiceCollection services)
{            
    // ...

    // Add RabbitMQ services
    services.Configure<RabbitOptions>(Configuration.GetSection("rabbit"));
    services.AddTransient<MessageListener>();
    services.AddTransient<MessageHandlerFactory>();
    services.AddTransient<IpSetMessageProcessor>();
    services.AddTransient<EndpointMessageProcessor>();
}

最后，更新Startup.Configure方法，以获取额外的IApplicationLifetime参数，并在ApplicationStarted/ApplicationStopped事件中启动/停止消息侦听器（尽管我不久前注意到使用IISExpress的ApplicationStopping事件存在一些问题，如在this question中）：

public MessageListener MessageListener { get; private set; }
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IApplicationLifetime appLifetime)
{
    appLifetime.ApplicationStarted.Register(() =>
    {
        MessageListener = app.ApplicationServices.GetService<MessageListener>();
        MessageListener.Start();
    });
    appLifetime.ApplicationStopping.Register(() =>
    {
        MessageListener.Stop();
    });

    // ...
}

尽管使用依赖注入是一个更好的解决方案，但在某些情况下，您必须使用静态方法（如扩展方法）。
对于这些情况，您可以向静态类添加静态属性，并在ConfigureServices方法中初始化它。
例如：

public static class EnumExtentions
{
    static public IStringLocalizerFactory StringLocalizerFactory { set; get; }

    public static string GetDisplayName(this Enum e)
    {
        var resourceManager = StringLocalizerFactory.Create(e.GetType());
        var key = e.ToString();
        var resourceDisplayName = resourceManager.GetString(key);

        return resourceDisplayName;
    }
}

和配置服务中：

EnumExtentions.StringLocalizerFactory = services.BuildServiceProvider().GetService<IStringLocalizerFactory>();

我知道我的回答晚了，但我想分享我是如何做到的。

首先：使用ServiceLocator是Antipattern，所以尽量不要使用它。在我的例子中，我需要它在我的DomainModel中调用MediatR来实现DomainEvents逻辑。
然而，我必须找到一种方法来调用DomainModel中的静态类，以从DI获取某个注册服务的示例。

因此，我决定使用HttpContext来访问IServiceProvider，但我需要从静态方法访问它，而不在域模型中提及它。
我们开始吧：
1-我创建了一个接口来 Package IServiceProvider

public interface IServiceProviderProxy
{
    T GetService<T>();
    IEnumerable<T> GetServices<T>();
    object GetService(Type type);
    IEnumerable<object> GetServices(Type type);
}

2-然后，我创建了一个静态类作为ServiceLocator访问点

public static class ServiceLocator
{
    private static IServiceProviderProxy diProxy;

    public static IServiceProviderProxy ServiceProvider => diProxy ?? throw new Exception("You should Initialize the ServiceProvider before using it.");

    public static void Initialize(IServiceProviderProxy proxy)
    {
        diProxy = proxy;
    }
}

3-我创建了IServiceProviderProxy的实现，它在内部使用IHttpContextAccessor

public class HttpContextServiceProviderProxy : IServiceProviderProxy
{
    private readonly IHttpContextAccessor contextAccessor;

    public HttpContextServiceProviderProxy(IHttpContextAccessor contextAccessor)
    {
        this.contextAccessor = contextAccessor;
    }

    public T GetService<T>()
    {
        return contextAccessor.HttpContext.RequestServices.GetService<T>();
    }

    public IEnumerable<T> GetServices<T>()
    {
        return contextAccessor.HttpContext.RequestServices.GetServices<T>();
    }

    public object GetService(Type type)
    {
        return contextAccessor.HttpContext.RequestServices.GetService(type);
    }

    public IEnumerable<object> GetServices(Type type)
    {
        return contextAccessor.HttpContext.RequestServices.GetServices(type);
    }
}

4-我应该像这样在DI中注册IServiceProviderProxy

public void ConfigureServices(IServiceCollection services)
{
    services.AddHttpContextAccessor();
    services.AddSingleton<IServiceProviderProxy, HttpContextServiceProviderProxy>();
    .......
}

5-最后一步是在应用程序启动时使用IServiceProviderProxy示例初始化ServiceLocator

public void Configure(IApplicationBuilder app, IHostingEnvironment env,IServiceProvider sp)
{
    ServiceLocator.Initialize(sp.GetService<IServiceProviderProxy>());
}

因此，现在您可以在DomainModel类中调用ServiceLocator“Or and needed place”并解析所需的依赖项。

public class FakeModel
{
    public FakeModel(Guid id, string value)
    {
        Id = id;
        Value = value;
    }

    public Guid Id { get; }
    public string Value { get; private set; }

    public async Task UpdateAsync(string value)
    {
        Value = value;
        var mediator = ServiceLocator.ServiceProvider.GetService<IMediator>();
        await mediator.Send(new FakeModelUpdated(this));
    }
}

以下是我对你的情况的看法：
如果可能，我将发送解析的服务作为参数

public static IMessageProcessor Create(string messageType, IIpSetService ipService)
{
    //
}

否则使用寿命将很重要。

如果服务是单例的，我只需要设置configure方法的依赖关系：

// configure method
public IApplicationBuilder Configure(IApplicationBuilder app)
{
    var ipService = app.ApplicationServices.GetService<IIpSetService>();
    MessageHandlerFactory.IIpSetService = ipService;
}

// static class
public static IIpSetService IpSetService;

public static IMessageProcessor Create(string messageType)
{
    // use IpSetService
}

如果服务生存期是有范围的，我将使用HttpContextAccessor：

//Startup.cs
public void ConfigureServices(IServiceCollection services)
{
    services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}

public IApplicationBuilder Configure(IApplicationBuilder app)
{
    var httpContextAccessor= app.ApplicationServices.GetService<IHttpContextAccessor>();
    MessageHandlerFactory.HttpContextAccessor = httpContextAccessor;
}

// static class
public static IHttpContextAccessor HttpContextAccessor;

public static IMessageProcessor Create(string messageType)
{
    var ipSetService = HttpContextAccessor.HttpContext.RequestServices.GetService<IIpSetService>();
    // use it
}

Here是ServiceLocator的一个很好的实现，它也使用了作用域，甚至可以用于IHttpContextAccessor！
只需将this class复制到代码中，然后注册ServiceLocator

ServiceActivator.Configure(app.ApplicationServices);

**重要说明 ：ServiceLocator被视为反模式，因此如果您有任何其他选择，请不要使用它！！！！

关于瓦希德·比塔尔的答复
太神奇了！对于.Net Core 6，我在Program.cs上做了：

builder.Services.AddSingleton<IServiceProviderProxy, HttpContextServiceProviderProxy>();

ServiceLocator.Initialize(app.Services.GetService<IServiceProviderProxy>());

您可以在Configure中获得服务引用：

app.UseMvc();
var myServiceRef = app.ApplicationServices.GetService<MyService>();

然后将其传递给init函数或在类上设置静态成员
当然，正如其他答案中所解释的，依赖注入将是一个更好的解决方案...