DotNETCore 学习笔记 依赖注入和多环境

Dependency Injection
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ASP.NET services can be configured with the following lifetimes:
 
Transient
Transient lifetime services are created each time they are requested. This lifetime works best for 
 
lightweight, stateless services.
 
Scoped
Scoped lifetime services are created once per request.
 
Singleton
Singleton lifetime services are created the first time they are requested (or when ConfigureServices is run 
 
if you specify an instance there) and then every subsequent request will use the same instance. If your 
 
application requires singleton behavior, allowing the services container to manage the service’s lifetime 
 
is recommended instead of implementing the singleton design pattern and managing your object’s lifetime in 
 
the class yourself.
 
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"dependencies" : {
  "Autofac": "4.0.0",
  "Autofac.Extensions.DependencyInjection": "4.0.0"
},
 
public IServiceProvider ConfigureServices(IServiceCollection services)
{
  services.AddMvc();
  // add other framework services
 
  // Add Autofac
  var containerBuilder = new ContainerBuilder();
  containerBuilder.RegisterModule<DefaultModule>();
  containerBuilder.Populate(services);
  var container = containerBuilder.Build();
  return new AutofacServiceProvider(container);
}
 
public class DefaultModule : Module
{
  protected override void Load(ContainerBuilder builder)
  {
    builder.RegisterType<CharacterRepository>().As<ICharacterRepository>();
  }
}
 
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Working with Multiple Environments
 
ASPNETCORE_ENVIRONMENT：Development, Staging, and Production
 
env.IsEnvironment("environmentname")
or
env.EnvironmentName == "Development" 
 
Startup{EnvironmentName} (for example StartupDevelopment)
 
Configure{EnvironmentName}() ConfigureDevelopment() 
 
Configure{EnvironmentName}Services(). ConfigureDevelopmentServices（）