Autofac 异常：无法解析构造函数“Void .ctor”的参数

使用 Autofac 时，有时候会遇到一个令人困惑的异常：“无法解析构造函数的参数”。这个异常通常出现在我们尝试解析一个类的实例时，Autofac 无法找到该类的构造函数的参数。这篇文章将详细介绍这个异常的原因和解决方法，并提供一个案例代码来说明如何处理这个异常。

var builder = new ContainerBuilder();
builder.RegisterType().As();
builder.RegisterType().As();
builder.RegisterType().As();

builder.RegisterType().As();
builder.RegisterType().As();

csharp
using Autofac;
using System;
public interface ILogger
{
    void Log(string message);
}
public class Logger : ILogger
{
    public void Log(string message)
    {
        Console.WriteLine("Logging: " + message);
    }
}
public interface IUserRepository
{
    void SaveUser(string username);
}
public class UserRepository : IUserRepository
{
    private readonly ILogger _logger;
    public UserRepository(ILogger logger)
    {
        _logger = logger;
    }
    public void SaveUser(string username)
    {
        _logger.Log("Saving user: " + username);
    }
}
public interface IUserService
{
    void CreateUser(string username);
}
public class UserService : IUserService
{
    private readonly IUserRepository _repository;
    public UserService(IUserRepository repository)
    {
        _repository = repository;
    }
    public void CreateUser(string username)
    {
        _repository.SaveUser(username);
    }
}
public class Program
{
    public static void Main()
    {
        var builder = new ContainerBuilder();
        builder.RegisterType().As();
        builder.RegisterType().As();
        builder.RegisterType().As();
        using (var container = builder.Build())
        {
            var userService = container.Resolve();
            userService.CreateUser("John");
        }
    }
}

Logging: Saving user: John