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(#34;{this.GetType().Name}被构造。。。");
}
public TestServiceB(ITestServiceA iTestServiceA)
{
Console.WriteLine(#34;{this.GetType().Name}被构造。。。");
}
public TestServiceC(ITestServiceB iTestServiceB)
{
Console.WriteLine(#34;{this.GetType().Name}被构造。。。");
}
public TestServiceD()
{
Console.WriteLine(#34;{this.GetType().Name}被构造。。。");
}
public TestServiceE(ITestServiceC serviceC)
{
Console.WriteLine(#34;{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();生成需要的实例
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().As().SingleInstance();}
//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(#34;invocation.Methond={invocation.Method}");
Console.WriteLine(#34;invocation.Arguments={string.Join(",", invocation.Arguments)}");
invocation.Proceed(); //继续执行
Console.WriteLine(#34;方法{invocation.Method}执行完成了");
}
}
