[.Net] .Net Core中使用Autofac替换自带的DI容器的示例

• 项目创建
  
• 方案演示
  
  
  
  • .Net Core自带DI
    
  
  
• 不同的特性
  
  
  
  • 批量注入
    
  • 属性注入
    
  • 存储并提取容器实例
    
  
  

[HttpGet]
public string Original()
{
  IUserService userService = new UserService();
  return userService.GetName("Original");
}

services.AddScoped<IUserService, UserService>();

public class DefaultController : ControllerBase
  {
    private readonly IUserService userService;
    public DefaultController(IUserService _userService)
    {
      this.userService = _userService;
    } 
   [HttpGet]
   public string CoreDI()
   {
     return userService.GetName("CoreDI");
   }
 }

public static IHostBuilder CreateHostBuilder(string[] args) =>
  Host.CreateDefaultBuilder(args)
    // 就是这句
    .UseServiceProviderFactory(new AutofacServiceProviderFactory())
    .ConfigureWebHostDefaults(webBuilder =>
    {
      webBuilder.UseStartup<Startup>();
    });

public class AutofacModuleRegister : Autofac.Module
{
  //重写Autofac管道Load方法，在这里注册注入
  protected override void Load(ContainerBuilder builder)
  {
    builder.RegisterType<UserService>().As<IUserService>();
 }
}

public void ConfigureContainer(ContainerBuilder builder)
{
  // 直接用Autofac注册我们自定义的 
  builder.RegisterModule(new AutofacModuleRegister());
}

public class DefaultController : ControllerBase
 {
   private readonly IUserService userService;
   public DefaultController(IUserService _userService)
   {
     this.userService = _userService;
   }
   [HttpGet]
   public string Autofac()
   {
     return userService.GetName("Autofac");
   }
 }

services.AddScoped<IProductService, ProductService>();
services.AddScoped<IOrderService, OrderService>();
......

// 服务项目程序集
Assembly service = Assembly.Load("XXX.Service");
// 服务接口项目程序集
Assembly iservice = Assembly.Load("XXX.IService");
builder.RegisterAssemblyTypes(service, iservice)
  .Where(t => t.FullName.EndsWith("Service") && !t.IsAbstract)
  .InstancePerLifetimeScope()
  .AsImplementedInterfaces();

private readonly IUserService userService;
private readonly IProductService productService;
public DefaultController(IUserService _userService, IProductService _productService)
{
  this.userService = _userService;
  this.productService = _productService;
}

[HttpGet]
public string Autofac()
{
  var name = userService.GetName("Autofac");
  return productService.Buy(name, "批量注入");
}

Assembly service = Assembly.Load("Autofac.Service");
Assembly iservice = Assembly.Load("Autofac.Service");
builder.RegisterAssemblyTypes(service, iservice)
  .Where(t => t.FullName.EndsWith("Service") && !t.IsAbstract)
  .InstancePerLifetimeScope()
  .AsImplementedInterfaces()
  .PropertiesAutowired(); // 属性注入

public IUserService userService { get; set; }
public IProductService productService { get; set; }

// 使用 ServiceBasedControllerActivator 替换 DefaultControllerActivator；
// Controller 默认是由 Mvc 模块管理的，不在 Ioc 容器中。替换之后，将放在 Ioc 容器中。
services.Replace(ServiceDescriptor.Transient<IControllerActivator, ServiceBasedControllerActivator>());

builder.RegisterTypes(GetAssemblyTypes<Startup>(type => typeof(ControllerBase).IsAssignableFrom(type)))
        .PropertiesAutowired();

// 基类实体 public class BaseEntity
  {
    public Class1 common_Class1 { get; set; }
    public string CreateId { get; set; }
    public void Create()
    {
      this.CreateId = common_Class1.getCurrentUserId();
    }
  }
  // 公共类
  public class Class1
  {
    public string getCurrentUserId()
    {
      return Guid.NewGuid().ToString();
    }
  }

builder.RegisterType<Class1>().PropertiesAutowired().InstancePerLifetimeScope();

public Class1 class1 { get; set; }
[HttpGet]
public string Autofac()
{
  return class1.getCurrentUserId();
}

public static class ContainerHelper
{
  public static ILifetimeScope ContainerBuilder { get; set; }
}

ContainerHelper.ContainerBuilder = app.ApplicationServices.CreateScope().ServiceProvider.GetAutofacRoot();

public void Create()
{
  if (common_Class1 == null)
  {
    using (var scope = ContainerHelper.ContainerBuilder.BeginLifetimeScope())
    {
      common_Class1 = scope.Resolve<Class1>();
    }
  }
  this.CreateId = common_Class1.getCurrentUserId();
}