DI 依賴注入、IOC 控制反轉(zhuǎn)以及 AOP 切面編程
Autofac 容器
Autofac 是一款.NET IoC 容器 . 它管理類之間的依賴關(guān)系, 從而使 應(yīng)用在規(guī)模及復(fù)雜性增長的情況下依然可以輕易地修改 . 它的實(shí)現(xiàn)方式是將常規(guī)的.net類當(dāng)做 組件 處理.
- 安裝 NuGet 程序包:
Autofac 6.0.0
- 創(chuàng)建一個(gè) ContainerBuiler
- 注冊(cè)接口和實(shí)現(xiàn)關(guān)系
- 通過 ContainerBuiler 的 Build 方法俺驶,得到 IContainer 容器
- 通過 IContainer 容器獲取實(shí)例
- 使用服務(wù)
-
ITestServiceA
和TestServiceA
public interface ITestServiceA
{
void Show();
}
public class TestServiceA : ITestServiceA
{
public TestServiceA()
{
Console.WriteLine($"{this.GetType().Name} 被構(gòu)造了...");
}
public void Show()
{
Console.WriteLine($"This is a {this.GetType().Name} Instance...");
}
}
- Program 中的
Main
方法
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
var container = builder.Build();
// 獲取服務(wù)實(shí)例
var testService = container.Resolve<ITestServiceA>();
testService.Show();
Autofac 多種注入方式
-
ITestServiceB
和TestServiceB
public interface ITestServiceB
{
void Show();
}
public class TestServiceB : ITestServiceB
{
private ITestServiceA _testServiceA;
public void SetService(ITestServiceA testServiceA)
{
_testServiceA = testServiceA;
}
public TestServiceB()
{
Console.WriteLine($"{this.GetType().Name} 被構(gòu)造了...");
}
public void Show()
{
// _testServiceA.Show();
Console.WriteLine($"This is a {this.GetType().Name} Instance...");
}
}
-
ITestServiceC
和TestServiceC
public interface ITestServiceC
{
void Show();
}
public class TestServiceC : ITestServiceC
{
public TestServiceC()
{
Console.WriteLine($"{this.GetType().Name} 被構(gòu)造了...");
}
public void Show()
{
Console.WriteLine($"This is a {this.GetType().Name} Instance...");
}
}
-
ITestServiceD
和TestServiceD
public interface ITestServiceD
{
void Show();
}
public class TestServiceD : ITestServiceD
{
public ITestServiceA TestServiceA { get; set; }
public ITestServiceB TestServiceB { get; set; }
public ITestServiceC TestServiceC { get; set; }
public TestServiceD()
{
Console.WriteLine($"{this.GetType().Name} 被構(gòu)造了...");
}
public void Show()
{
// TestServiceA.Show();
// TestServiceB.Show();
// TestServiceC.Show();
Console.WriteLine($"This is a {this.GetType().Name} Instance...");
}
}
- 構(gòu)造函數(shù)注入
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceB>().As<ITestServiceB>();
builder.RegisterType<TestServiceC>().As<ITestServiceC>();
builder.RegisterType<TestServiceD>().As<ITestServiceD>();
var container = builder.Build();
// 獲取服務(wù)實(shí)例
var testService = container.Resolve<ITestServiceA>();
testService.Show();
- 屬性注入
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceB>().As<ITestServiceB>();
builder.RegisterType<TestServiceC>().As<ITestServiceC>();
builder.RegisterType<TestServiceD>().As<ITestServiceD>().PropertiesAutowired();
var container = builder.Build();
// 獲取服務(wù)實(shí)例
var testService = container.Resolve<ITestServiceD>();
testService.Show();
- 方法注入
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceB>().OnActivated(e =>
e.Instance.SetService(e.Context.Resolve<ITestServiceA>())
).As<ITestServiceB>();
builder.RegisterType<TestServiceC>().As<ITestServiceC>();
builder.RegisterType<TestServiceD>().As<ITestServiceD>();
var container = builder.Build();
// 獲取服務(wù)實(shí)例
var testService = container.Resolve<ITestServiceB>();
testService.Show();
Autofac 生命周期
- InstancePerDependency :默認(rèn)模式幸逆,每次調(diào)用,都會(huì)重新實(shí)例化對(duì)象暮现;每次請(qǐng)求都創(chuàng)建一個(gè)新的對(duì)象还绘;
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>().InstancePerDependency();
var container = builder.Build();
var testServiceA = container.Resolve<ITestServiceA>();
var testServiceA1 = container.Resolve<ITestServiceA>();
Console.WriteLine(object.ReferenceEquals(testServiceA,testServiceA1));
- SingleInstance :單例模式,每次調(diào)用栖袋,都會(huì)使用同一個(gè)實(shí)例化的對(duì)象拍顷;每次都用同一個(gè)對(duì)象;
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>().SingleInstance();
var container = builder.Build();
var testServiceA = container.Resolve<ITestServiceA>();
var testServiceA1 = container.Resolve<ITestServiceA>();
Console.WriteLine(object.ReferenceEquals(testServiceA,testServiceA1));
- InstancePerLifetimeScope : 同一個(gè)生命周期域中塘幅,每次調(diào)用昔案,都會(huì)使用同一個(gè)實(shí)例化的對(duì)象;每次都用同一個(gè)對(duì)象电媳;且每個(gè)不同的生命周期域中的實(shí)例是唯一的踏揣,不共享的。
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>().InstancePerLifetimeScope();
var container = builder.Build();
ITestServiceA testServiceA15;
ITestServiceA testServiceA16;
using (var scope1 = container.BeginLifetimeScope())
{
var testServiceA11 = scope1.Resolve<ITestServiceA>();
var testServiceA12 = scope1.Resolve<ITestServiceA>();
Console.WriteLine(object.ReferenceEquals(testServiceA11,testServiceA12));
testServiceA15 = testServiceA12;
}
using (var scope1 = container.BeginLifetimeScope())
{
var testServiceA13 = scope1.Resolve<ITestServiceA>();
var testServiceA14 = scope1.Resolve<ITestServiceA>();
Console.WriteLine(object.ReferenceEquals(testServiceA13,testServiceA14));
testServiceA16 = testServiceA14;
}
Console.WriteLine(object.ReferenceEquals(testServiceA15,testServiceA16));
- InstancePerMatchingLifetimeScope : 同一個(gè)匹配的生命周期域中匾乓,每次調(diào)用捞稿,都會(huì)使用同一個(gè)實(shí)例化的對(duì)象;每次都用同一個(gè)對(duì)象;且每個(gè)不匹配的生命周期域中的實(shí)例是唯一的娱局,不共享的彰亥。
var builder = new ContainerBuilder();
builder.RegisterType<TestServiceA>().As<ITestServiceA>()
.InstancePerMatchingLifetimeScope("Run2948");
var container = builder.Build();
ITestServiceA testServiceA15;
ITestServiceA testServiceA16;
using (var scope1 = container.BeginLifetimeScope("Run2948"))
{
var testServiceA11 = scope1.Resolve<ITestServiceA>();
using (var scope2 = container.BeginLifetimeScope())
{
var testServiceA12 = scope2.Resolve<ITestServiceA>();
Console.WriteLine(object.ReferenceEquals(testServiceA11,testServiceA12));
}
testServiceA15 = testServiceA11;
}
using (var scope1 = container.BeginLifetimeScope("Run2948"))
{
var testServiceA13 = scope1.Resolve<ITestServiceA>();
using (var scope2 = container.BeginLifetimeScope())
{
var testServiceA14 = scope2.Resolve<ITestServiceA>();
Console.WriteLine(object.ReferenceEquals(testServiceA13,testServiceA14));
}
testServiceA16 = testServiceA13;
}
Console.WriteLine(object.ReferenceEquals(testServiceA15,testServiceA16));
InstancePerOwned : 在一個(gè)所擁有的實(shí)例創(chuàng)建的生命周期中,每次調(diào)用衰齐,都會(huì)使用同一個(gè)實(shí)例化的對(duì)象任斋;每次都用同一個(gè)對(duì)象;(較少使用)
InstancePerHttpRequest : 同一次Http請(qǐng)求上下文中耻涛,每次調(diào)用仁卷,都會(huì)使用同一個(gè)實(shí)例化的對(duì)象;每次都用同一個(gè)對(duì)象犬第;僅適用于 ASP.NET (CORE) MVC 或 WebForm 應(yīng)用程序
Autofac 支持配置文件
- 安裝 NuGet 程序包:
Autofac.Extensions.DependencyInjection 7.1.0
锦积、Autofac.Configuration 6.0.0
- 新建配置文件(指定接口和實(shí)現(xiàn)的對(duì)應(yīng)關(guān)系)
autofac.json
:
{
"components":[
{
"type: "One.Services.TestServiceA,One",
"services": [
{
"type": "One.Services.ITestServiceA,One"
}
],
"instanceScope": "single-instance",
"injectProperties": true
},
{
"type: "One.Services.TestServiceB,One",
"services": [
{
"type": "One.Services.ITestServiceB,One"
}
],
"instanceScope": "single-instance",
"injectProperties": true
},
{
"type: "One.Services.TestServiceC,One",
"services": [
{
"type": "One.Services.ITestServiceC,One"
}
],
"instanceScope": "single-instance",
"injectProperties": true
},
{
"type: "One.Services.TestServiceD,One",
"services": [
{
"type": "One.Services.ITestServiceD,One"
}
],
"instanceScope": "single-instance",
"injectProperties": true
}
]
}
- 讀取配置文件,完成服務(wù)對(duì)應(yīng)關(guān)系的注冊(cè)
var builder = new ContainerBuilder();
var config = new ConfigurationBuilder();
var configSource = new JsonConfigurationSource()
{
Path = "Config/autofac.json",
Optional = false,
ReloadOnChange = true
};
config.Add(configSource);
var configModule = new ConfigurationModule(config.Build());
builder.RegisterModule(configModule);
var container = builder.Build();
// 獲取服務(wù)實(shí)例
var testServiceA = container.Resolve<ITestServiceA>();
var testServiceD = container.Resolve<ITestServiceD>();
testServiceD.Show();
- 新建 ITestServiceA 的新版實(shí)現(xiàn)類
TestServiceUpdate
public class TestServiceUpdate : ITestServiceA
{
public TestServiceUpdate()
{
Console.WriteLine($"{this.GetType().Name} 被構(gòu)造了...");
}
public void Show()
{
Console.WriteLine($"This is a {this.GetType().Name} Instance...");
}
}
- 通過修改配置文件
autofac.json
來實(shí)現(xiàn)快速實(shí)現(xiàn) ITestServiceA 的實(shí)現(xiàn)的重新定義:
{
"components":[
{
"type: "One.Services.TestServiceUpdate,One",
"services": [
{
"type": "One.Services.ITestServiceA,One"
}
],
"instanceScope": "single-instance",
"injectProperties": true
},
// ...
Autofac 整合 .NET 5 MVC
安裝 NuGet 程序包:
Autofac.Extensions.DependencyInjection 7.1.0
Program文件中指定 Autofac 工廠替換默認(rèn)工廠:
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
}).UseServiceProviderFactory(new AutofacServiceProviderFactory());
- 在 Startup 類中增加 ConfigureContainer 方法:
public void ConfigureContainer(ContainerBuilder builder)
{
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
}
- 通過控制器構(gòu)造函數(shù)注入歉嗓,獲取實(shí)例
[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
private readonly ITestServiceA _serviceA;
public ValuesController(ITestServiceA serviceA
{
_serviceA = serviceA;
}
[HttpGet]
public IActionResult Get()
{
_serviceA.Show();
return Ok();
}
}
- 使用 IServiceCollection 注冊(cè)的服務(wù)丰介,將來也會(huì)交給 Autofac 管理
public void ConfigureServices(IServiceCollection services)
{
#region IServiceCollection 注冊(cè)的服務(wù),將來也會(huì)交給 Autofac 處理
services.AddTransient<ITestServiceA, TestServiceA>();
services.AddTransient<ITestServiceB, TestServiceB>();
services.AddTransient<ITestServiceC, TestServiceC>();
#endregion
}
public void ConfigureContainer(ContainerBuilder builder)
{
// builder.RegisterType<TestServiceA>().As<ITestServiceA>();
// builder.RegisterType<TestServiceB>().As<ITestServiceB>();
// builder.RegisterType<TestServiceC>().As<ITestServiceC>();
builder.RegisterType<TestServiceD>().As<ITestServiceD>();
}
Autofac 支持控制器屬性注入
控制器本身是一個(gè)類鉴分,它的實(shí)例其實(shí)是有 IControllerActivator 來創(chuàng)建的哮幢。
- 指定控制器的實(shí)例由容器來創(chuàng)建
public void ConfigureServices(IServiceCollection services)
{
// ...
#region 指定控制器的實(shí)例由容器來創(chuàng)建
services.Replace(ServiceDescriptor.Transient<IControllerActivator, ServiceBasedControllerActivator>());
#endregion
}
- 注冊(cè)控制器的抽象和具體的關(guān)系
public void ConfigureContainer(ContainerBuilder builder)
{
builder.RegisterType<TestServiceA>().As<ITestServiceA>().PropertiesAutowired();
builder.RegisterType<TestServiceB>().As<ITestServiceB>();
#region 注冊(cè)所有控制器的關(guān)系及控制器實(shí)例化所需要的組件
var controllersTypesInAssembly = typeof(Startup).Assembly.GetExportedTypes()
.Where(type => typeof(ControllerBase).IsAssignableFrom(type)).ToArray();
builder.RegisterTypes(controllersTypesInAssembly)
.PropertiesAutowired();
#endregion
}
- 在控制器內(nèi)定義屬性
[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
public ITestServiceA TestServiceA { get; set; }
public ITestServiceB TestServiceB { get; set; }
[HttpGet]
public IActionResult Get()
{
TestServiceA.Show();
TestServiceB.Show();
return Ok();
}
}
- 擴(kuò)展:自己控制哪些屬性需要做依賴注入(默認(rèn)是讓控制器中的屬性都依賴注入)
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public class AutowaredAttribute : Attribute { }
public class PropertySelector : IPropertySelector
{
public bool InjectProperty(PropertyInfo propertyInfo, object instance)
{
return propertyInfo.CustomAttributes.Any(ca => ca.AttributeType == typeof(AutowaredAttribute));
}
}
public void ConfigureContainer(ContainerBuilder builder)
{
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceB>().As<ITestServiceB>();
#region 注冊(cè)所有控制器的關(guān)系及控制器實(shí)例化所需要的組件
var controllersTypesInAssembly = typeof(Startup).Assembly.GetExportedTypes()
.Where(type => typeof(ControllerBase).IsAssignableFrom(type)).ToArray();
builder.RegisterTypes(controllersTypesInAssembly)
.PropertiesAutowired(new PropertySelector());
#endregion
}
[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
[Autowared]
public ITestServiceA TestServiceA { get; set; }
public ITestServiceB TestServiceB { get; set; }
[HttpGet]
public IActionResult Get()
{
TestServiceA.Show();
TestServiceB.Show();
return Ok();
}
}
Autofac 單實(shí)例多實(shí)現(xiàn)
public void ConfigureContainer(ContainerBuilder builder)
{
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceUpdate>().As<ITestServiceA>();
}
- 如果多個(gè)實(shí)現(xiàn)同時(shí)注冊(cè),則后注冊(cè)的實(shí)現(xiàn)就會(huì)覆蓋先注冊(cè)的實(shí)現(xiàn)志珍,最后將返回最后一個(gè)注冊(cè)的實(shí)現(xiàn)橙垢。
- 如果多個(gè)實(shí)現(xiàn)同時(shí)注冊(cè),可以通過一個(gè) IEnumerable<實(shí)例> 來獲取到所有的實(shí)現(xiàn)伦糯。
private readonly IEnumerable<ITestServiceA> _testServiceAs;
public ValuesController(IEnumerable<ITestServiceA> testServiceAs)
{
_testServiceAs = testServiceAs;
}
- 當(dāng)多個(gè)實(shí)現(xiàn)同時(shí)注冊(cè)后柜某,可以通過以下方式繼續(xù)注冊(cè) 實(shí)例 的所有實(shí)現(xiàn)。從而可以在控制器中直接使用具體實(shí)現(xiàn)類作為實(shí)現(xiàn)敛纲。
public void ConfigureContainer(ContainerBuilder builder)
{
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceUpdate>().As<ITestServiceA>();
builder.RegisterSource(new AnyConcreteTypeNotAlreadyRegisteredSource(type => type.IsAssignableTo<ITestServiceA>()));
}
private readonly TestServiceA _testServiceA;
private readonly TestServiceUpdate _testServiceUpdate;
public ValuesController(TestServiceA testServiceA,TestServiceUpdate testServiceUpdate)
{
_testServiceA = testServiceA;
_testServiceUpdate = testServiceUpdate;
}
- 擴(kuò)展:Autofac 的注冊(cè)邏輯可以通過 Module 來拆分管理喂击。
public class AutofacModule : Autofac.Module
{
protected override void Load(ContainerBuilder builder)
{
// base.Load(builder);
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceUpdate>().As<ITestServiceA>();
builder.RegisterSource(new AnyConcreteTypeNotAlreadyRegisteredSource(type => type.IsAssignableTo<ITestServiceA>()));
}
}
public void ConfigureContainer(ContainerBuilder builder)
{
// builder.RegisterModule(new AutofacModule());
builder.RegisterModule<AutofacModule>();
}
Autofac 支持 AOP
AOP 面向切面編程,通過預(yù)編譯方式和運(yùn)行期動(dòng)態(tài)代理實(shí)現(xiàn)程序功能的統(tǒng)一維護(hù)的一種技術(shù)淤翔。Autofac 的AOP是通過 Castle(也是一個(gè)容器)項(xiàng)目的名為 Autofac.Extras.DynamicProxy 核心部分實(shí)現(xiàn)的翰绊,顧名思義其實(shí)現(xiàn)方式為動(dòng)態(tài)代理。
安裝 NuGet 程序包:
Castle.Core 4.4.1
旁壮、Autofac.Extras.DynamicProxy 6.0.0
新建自定義 AOP 攔截器
public class CustomAutofacAop : IInterceptor
{
public void Intercept(IInvocation invocation)
{
{
Console.WriteLine("方法執(zhí)行前...");
}
invocation.Proceed();
{
Console.WriteLine("方法執(zhí)行后...");
}
}
}
- 在接口上標(biāo)記需要使用的攔截器
[Intercept(typeof(CustomAutofacAop))]
public interface ITestServiceA
{
void Show();
}
- 注冊(cè)自定義攔截器监嗜,并允許實(shí)例接口使用攔截器
public void ConfigureContainer(ContainerBuilder builder)
{
//builder.RegisterType<CustomAutofacAop>();
builder.RegisterType(typeof(CustomAutofacAop));
builder.RegisterType<TestServiceA>().As<ITestServiceA>();
builder.RegisterType<TestServiceUpdate>().As<ITestServiceA>().EnableInterfaceInterceptors();
}
- 在控制器中調(diào)用實(shí)例,即可成功執(zhí)行 AOP 攔截器
[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
private readonly TestServiceA _testServiceA;
private readonly TestServiceUpdate _testServiceUpdate;
public ValuesController(TestServiceA testServiceA,TestServiceUpdate testServiceUpdate)
{
_testServiceA = testServiceA;
_testServiceUpdate = testServiceUpdate;
}
public IActionResult Get()
{
_testServiceA.Show();
_testServiceUpdate.Show();
return Ok();
}
}