- A+
所属分类：.NET技术
一、配置文件的读取
利用Startup类中的configuration读取appsettings.json中的配置
{ "Logging": { "LogLevel": { "Default": "Warning" } }, "option1": "value1_from_json", "option2": 2, "subsection": { "suboption1": "subvalue1_from_json", "Read": [ "Data Source=.; Database=Customers_New1; User ID=sa; Password=Passw0rd; MultipleActiveResultSets=True", "Data Source=ElevenPC; Database=Customers_New2; User ID=sa; Password=Passw0rd; MultipleActiveResultSets=True", "Data Source=.; Database=Customers_New3; User ID=sa; Password=Passw0rd; MultipleActiveResultSets=True" ] }, "wizards": [ { "Name": "Gandalf", "Age": "1000" }, { "Name": "Harry", "Age": "17" } ], "AllowedHosts": "*" } public IConfiguration Configuration { get; } public Startup(IConfiguration configuration) { Configuration = configuration; } this.Configuration["Option1"] this.Configuration["subsection:suboption1"] string[] _SqlConnectionStringRead = this._iConfiguration.GetSection("subsection").GetSection("Read").GetChildren().Select(s => s.Value).ToArray(); 二、自带IOC容器
1.基本使用
- NuGet安装引用Microsoft.Extensions.DependencyInjection;
- 实例化容器
- 注册服务
- 创建一个System.IServiceProvider提供程序
- 创建实例
using Microsoft.Extensions.DependencyInjection; IServiceCollection container = new ServiceCollection(); container.AddTransient<Interface,class>(); IServiceProvider provider = container.BuildServiceProvider(); _Interface interface = provider.GetService<_Interface>() 2.服务类型
1.container.AddTransient为瞬时生命周期,每次创建都是一个全新的实例
IServiceCollection container = new ServiceCollection(); container.AddTransient<Interface,class>(); IServiceProvider provider = container.BuildServiceProvider(); _Interface interface = provider.GetService<_Interface>(); _Interface interface2 = provider.GetService<_Interface>(); bool bResult = object.ReferenceEquals(interface, interface2); //b is false 2.container.AddSingleton单例：全容器都是一个
IServiceCollection container = new ServiceCollection(); container.AddSingleton<Interface,class>(); IServiceProvider provider = container.BuildServiceProvider(); _Interface interface = provider.GetService<_Interface>(); _Interface interface2 = provider.GetService<_Interface>(); bool bResult = object.ReferenceEquals(interface, interface2); //b is True 3.container.AddScoped请求单例，一个请求代表一个作用域
IServiceCollection container = new ServiceCollection(); container.AddScoped<Interface,class>(); IServiceProvider provider = container.BuildServiceProvider(); //创建一个Scope作用域,那么由这个域创建的实例是独立的（相较Scope1） IServiceScope Scope = provider.CreateScope(); //创建一个Scope1作用域,那么由这个域创建的实例是独立的 IServiceScope Scope1 = provider.CreateScope(); _Interface interface =Scope.ServiceProvider.GetService<_Interface>(); _Interface interface2 = Scope1.ServiceProvider.GetService<_Interface>(); bool bResult = object.ReferenceEquals(interface, interface2); //b is false 三、自带IOC容器(IServiceCollection)基础
1.生命周期
1.瞬时，即时构造，即时销毁
services.AddTransient<ITestServiceA, TestServiceA>(); 2.单例，永远只构造一次
services.AddSingleton<ITestServiceB, TestServiceB>(); 3.作用域单例，一次请求只构造一个
services.AddScoped<ITestServiceC, TestServiceC>(); 2.实例解析
public TestServiceA() { Console.WriteLine($"{this.GetType().Name}被构造。。。"); } public TestServiceB(ITestServiceA iTestServiceA) { Console.WriteLine($"{this.GetType().Name}被构造。。。"); } public TestServiceC(ITestServiceB iTestServiceB) { Console.WriteLine($"{this.GetType().Name}被构造。。。"); } public TestServiceD() { Console.WriteLine($"{this.GetType().Name}被构造。。。"); } public TestServiceE(ITestServiceC serviceC) { Console.WriteLine($"{this.GetType().Name}被构造。。。"); } //1.A类构造 //2.B类构造需要A类 //3.C类构造需要B类 //4.D类构造 //5.E类构造需要C类 //瞬时 services.AddTransient<ITestServiceA, TestServiceA>(); //单例 services.AddSingleton<ITestServiceB, TestServiceB>(); //作用域单例 services.AddScoped<ITestServiceC, TestServiceC>(); //瞬时 services.AddTransient<ITestServiceD, TestServiceD>(); //瞬时 services.AddTransient<ITestServiceE, TestServiceE>(); 第一次请求解析
1.开始构造A类，因为是瞬时生命周期那么第一次请求就会被构造，然后销毁
2.在构造B类时需要A类，那么会首先构造A类(因为A类瞬时上一次已经被销毁)，然后构造B类为单例
3.开始构造C，在构造时需要B类，因为B类全局单例，那就会直接构造C为作用域单例
4.直接构造瞬时D类
5.开始构造E类，构造式需要C类，因为C类为作用域单例，那么就会直接构造E类为瞬时
第一次请求结论
- 输出A
- 输出A，B
- 输出C
- 输出D
- 输出E
第二次请求解析
1.开始构造A类，因为是瞬时生命周期那么第二次请求就会重新被构造，然后销毁
2.在构造B类时因为在第一次请求时已经构造为单例，所以不再被构造
3.开始重新构造C，因为C在第二次请求为新的作用域,在构造时需要B类，因为B类全局单例，那就会直接构造C为作用域单例
4.直接构造瞬时D类
5.开始构造E类，构造式需要C类，因为C类为作用域单例，那么就会直接构造E类为瞬时
第二次请求结论
1.输出A
2.输出C
3.输出D
4.输出E
如果不想通过构造全部自动注入,能自定义注入
1.using Microsoft.Extensions.DependencyInjection;
2.首先注入 IServiceProvider serviceProvider，利用serviceProcider.GetService
四、利用AutoFac容器替换自带容器
1.下载Autofac.Extensions.DependencyInjection和Autofac包
2.在Program网站启动时替换默认IOC工厂实例为Autofac，UseServiceProviderFactory(new AutofacServiceProviderFactory())
3.在Startup类中添加方法public void ConfigureContainer(ContainerBuilder services){services.RegisterType
//返回值为IServiceProvider public IServiceProvider ConfigureContainer(ContainerBuilder services) { services.Configure<CookiePolicyOptions>(options => { options.CheckConsentNeeded = context => true; options.MinimumSameSitePolicy = SameSiteMode.None; }); services.AddSession(); services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2); //services.RegisterType<TestServiceE>().As<ITestServiceE>().SingleInstance(); services.RegisterModule<CustomMoudle>(); } 1.批量注册模块
public class CustomAutofacModule : Module { //重新load 添加注册服务 //可以实现实例控制 //接口约束 protected override void Load(ContainerBuilder containerBuilder) { containerBuilder.Register(c => new CustomAutofacAop()); //设置为属性注入 containerBuilder.RegisterType<TestServiceA>().As<ITestServiceA>().SingleInstance().PropertiesAutowired(); containerBuilder.RegisterType<TestServiceC>().As<ITestServiceC>(); containerBuilder.RegisterType<TestServiceB>().As<ITestServiceB>(); containerBuilder.RegisterType<TestServiceD>().As<ITestServiceD>(); containerBuilder.RegisterType<A>().As<IA>().EnableInterfaceInterceptors(); } } 五、利用AutoFac实现AOP
1.基本使用
1.NuGet安装引用Autofac.Extras.DynamicProxy
2.引用using Autofac.Extras.DynamicProxy;
3.创建类库继承自IInterceptor实现接口
4.自定义的Autofac的AOP扩展
//注册，模块 public class CustomAutofacModule : Module { //重新load 添加注册服务 //可以实现实例控制 //接口约束 protected override void Load(ContainerBuilder containerBuilder) { //注册AOP containerBuilder.Register(c => new CustomAutofacAop()); //开启aop扩展 containerBuilder.RegisterType<A>().As<IA>().EnableInterfaceInterceptors(); } } public class CustomAutofacAop : IInterceptor { public void Intercept(IInvocation invocation) { Console.WriteLine($"invocation.Methond={invocation.Method}"); Console.WriteLine($"invocation.Arguments={string.Join(",", invocation.Arguments)}"); invocation.Proceed(); //继续执行 Console.WriteLine($"方法{invocation.Method}执行完成了"); } } 
