public interface IServiceContainerBuilder

{

IServiceContainerBuilder Add(ServiceDefinition item);

IServiceContainerBuilder TryAdd(ServiceDefinition item);

IServiceContainer Build();

}

public class ServiceContainerBuilder : IServiceContainerBuilder

{

private readonly List<ServiceDefinition> _services = new List<ServiceDefinition>();

public IServiceContainerBuilder Add(ServiceDefinition item)

{

if (_services.Any(_ => _.ServiceType == item.ServiceType && _.GetImplementType() == item.GetImplementType()))

{

return this;

}

_services.Add(item);

return this;

}

public IServiceContainerBuilder TryAdd(ServiceDefinition item)

{

if (_services.Any(_ => _.ServiceType == item.ServiceType))

{

return this;

}

_services.Add(item);

return this;

}

public IServiceContainer Build() => new ServiceContainer(_services);

}

public interface IServiceContainer : IScope, IServiceProvider

{

IServiceContainer CreateScope();

}

internal class ServiceContainer : IServiceContainer

{

private readonly IReadOnlyList<ServiceDefinition> _services;

public ServiceContainer(IReadOnlyList<ServiceDefinition> serviceDefinitions)

{

_services = serviceDefinitions;

// ...

}

// 此處約省略一萬(wàn)行代碼 ...

}

public interface IServiceContainerModule

{

void ConfigureServices(IServiceContainerBuilder serviceContainerBuilder);

}

public abstract class ServiceContainerModule : IServiceContainerModule

{

public abstract void ConfigureServices(IServiceContainerBuilder serviceContainerBuilder);

}

public class TestServiceContainerModule : ServiceContainerModule

{

public override void ConfigureServices(IServiceContainerBuilder serviceContainerBuilder)

{

serviceContainerBuilder.AddSingleton<IIdGenerator>(GuidIdGenerator.Instance);

}

}

public static IServiceContainerBuilder RegisterAssemblyModules(

[NotNull] this IServiceContainerBuilder serviceContainerBuilder, params Assembly[] assemblies)

{

#if NET45

// 解決 asp.net 在 IIS 下應(yīng)用程序域被回收的問題

// https://autofac.readthedocs.io/en/latest/register/scanning.html#iis-hosted-web-applications

if (null == assemblies || assemblies.Length == 0)

{

if (System.Web.Hosting.HostingEnvironment.IsHosted)

{

assemblies = System.Web.Compilation.BuildManager.GetReferencedAssemblies()

.Cast<Assembly>().ToArray();

}

}

#endif

if (null == assemblies || assemblies.Length == 0)

{

assemblies = AppDomain.CurrentDomain.GetAssemblies();

}

foreach (var type in assemblies.WhereNotNull().SelectMany(ass => ass.GetTypes())

.Where(t => t.IsClass && !t.IsAbstract && typeof(IServiceContainerModule).IsAssignableFrom(t))

)

{

try

{

if (Activator.CreateInstance(type) is ServiceContainerModule module)

{

module.ConfigureServices(serviceContainerBuilder);

}

}

catch (Exception e)

{

Console.WriteLine(e);

}

}

return serviceContainerBuilder;

}

public class DependencyInjectionTest : IDisposable

{

private readonly IServiceContainer _container;

public DependencyInjectionTest()

{

var containerBuilder = new ServiceContainerBuilder();

containerBuilder.AddSingleton<IConfiguration>(new ConfigurationBuilder().Build());

containerBuilder.AddScoped<IFly, MonkeyKing>();

containerBuilder.AddScoped<IFly, Superman>();

containerBuilder.AddScoped<HasDependencyTest>();

containerBuilder.AddScoped<HasDependencyTest1>();

containerBuilder.AddScoped<HasDependencyTest2>();

containerBuilder.AddScoped<HasDependencyTest3>();

containerBuilder.AddScoped(typeof(HasDependencyTest4<>));

containerBuilder.AddTransient<WuKong>();

containerBuilder.AddScoped<WuJing>(serviceProvider => new WuJing());

containerBuilder.AddSingleton(typeof(GenericServiceTest<>));

containerBuilder.RegisterAssemblyModules();

_container = containerBuilder.Build();

}

[Fact]

public void Test()

{

var rootConfig = _container.ResolveService<IConfiguration>();

Assert.Throws<InvalidOperationException>(() => _container.ResolveService<IFly>());

Assert.Throws<InvalidOperationException>(() => _container.ResolveRequiredService<IDependencyResolver>());

using (var scope = _container.CreateScope())

{

var config = scope.ResolveService<IConfiguration>();

Assert.Equal(rootConfig, config);

var fly1 = scope.ResolveRequiredService<IFly>();

var fly2 = scope.ResolveRequiredService<IFly>();

Assert.Equal(fly1, fly2);

var wukong1 = scope.ResolveRequiredService<WuKong>();

var wukong2 = scope.ResolveRequiredService<WuKong>();

Assert.NotEqual(wukong1, wukong2);

var wuJing1 = scope.ResolveRequiredService<WuJing>();

var wuJing2 = scope.ResolveRequiredService<WuJing>();

Assert.Equal(wuJing1, wuJing2);

var s0 = scope.ResolveRequiredService<HasDependencyTest>();

s0.Test();

Assert.Equal(s0._fly, fly1);

var s1 = scope.ResolveRequiredService<HasDependencyTest1>();

s1.Test();

var s2 = scope.ResolveRequiredService<HasDependencyTest2>();

s2.Test();

var s3 = scope.ResolveRequiredService<HasDependencyTest3>();

s3.Test();

var s4 = scope.ResolveRequiredService<HasDependencyTest4<string>>();

s4.Test();

using (var innerScope = scope.CreateScope())

{

var config2 = innerScope.ResolveRequiredService<IConfiguration>();

Assert.True(rootConfig == config2);

var fly3 = innerScope.ResolveRequiredService<IFly>();

fly3.Fly();

Assert.NotEqual(fly1, fly3);

}

var flySvcs = scope.ResolveServices<IFly>();

foreach (var f in flySvcs)

f.Fly();

}

var genericService1 = _container.ResolveRequiredService<GenericServiceTest<int>>();

genericService1.Test();

var genericService2 = _container.ResolveRequiredService<GenericServiceTest<string>>();

genericService2.Test();

}

public void Dispose()

{

_container.Dispose();

}

}