什么是AspectCore Project ?
AspectCore Project 是适用于Asp.Net Core 平台的轻量级 Aop(Aspect-oriented programming) 解决方案，它更好的遵照Asp.Net Core的模块化开辟理念，运用AspectCore能够更轻易构建低耦合、易扩大的Web应用程序。AspectCore运用Emit完成高效的动态代办从而不依靠任何第三方Aop库。
开使运用AspectCore
启动 Visual Studio。从 File 菜单, 挑选 New > Project。挑选 ASP.NET Core Web Application 项目模版，建立新的 ASP.NET Core Web Application 项目。
从 Nuget 装置 AspectCore.Extensions.DependencyInjection package:
PM> Install-Package AspectCore.Extensions.DependencyInjection
在平常情况下能够运用笼统的InterceptorAttribute自定义特征类，它完成IInterceptor接口。AspectCore默许完成了基于Attribute的拦截器设置。我们的自定义拦截器看起来像下面如许:
public class CustomInterceptorAttribute : InterceptorAttribute
{
public async override Task Invoke(IAspectContext context, AspectDelegate next)
{
try
{
Console.WriteLine("Before service call");
await next(context);
}
catch (Exception)
{
Console.WriteLine("Service threw an exception!");
throw;
}
finally
{
Console.WriteLine("After service call");
}
}
}
定义ICustomService接口和它的完成类CustomService:
public interface ICustomService
{
[CustomInterceptor]
void Call();
}
public class CustomService : ICustomService
{
public void Call()
{
Console.WriteLine("service calling...");
}
}
在HomeController中注入ICustomService:
public class HomeController : Controller
{
private readonly ICustomService _service;
public HomeController(ICustomService service)
{
_service = service;
}
public IActionResult Index()
{
_service.Call();
return View();
}
}
注册ICustomService，接着，在ConfigureServices中设置建立代办范例的容器:
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddTransient<ICustomService, CustomService>();
services.AddMvc();
services.AddAspectCore();
return services.BuildAspectCoreServiceProvider();
}
拦截器设置。起首装置AspectCore.Extensions.Configuration package：
PM> Install-Package AspectCore.Extensions.Configuration
全局拦截器。运用AddAspectCore(Action<AspectCoreOptions>)的重载要领，个中AspectCoreOptions供应InterceptorFactories注册全局拦截器:
services.AddAspectCore(config =>
{
config.InterceptorFactories.AddTyped<CustomInterceptorAttribute>();
});
带组织器参数的全局拦截器，在CustomInterceptorAttribute中增加带参数的组织器：
public class CustomInterceptorAttribute : InterceptorAttribute
{
private readonly string _name;
public CustomInterceptorAttribute(string name)
{
_name = name;
}
public async override Task Invoke(AspectContext context, AspectDelegate next)
{
try
{
Console.WriteLine("Before service call");
await next(context);
}
catch (Exception)
{
Console.WriteLine("Service threw an exception!");
throw;
}
finally
{
Console.WriteLine("After service call");
}
}
}
修正全局拦截器注册:
services.AddAspectCore(config =>
{
config.InterceptorFactories.AddTyped<CustomInterceptorAttribute>(args: new object[] { "custom" });
});
作为效劳的全局拦截器。在ConfigureServices中增加：
services.AddTransient<CustomInterceptorAttribute>(provider => new CustomInterceptorAttribute("service"));
修正全局拦截器注册:
services.AddAspectCore(config =>
{
config.InterceptorFactories.AddServiced<CustomInterceptorAttribute>();
});
作用于特定Service或Method的全局拦截器，下面的代码演示了作用于带有Service后缀的类的全局拦截器：
services.AddAspectCore(config =>
{
config.InterceptorFactories.AddTyped<CustomInterceptorAttribute>(method => method.DeclaringType.Name.EndsWith("Service"));
});
运用通配符的特定全局拦截器：
services.AddAspectCore(config =>
{
config.InterceptorFactories.AddTyped<CustomInterceptorAttribute>(PredicateFactory.ForService("*Service"));
});
在AspectCore中供应NonAspectAttribute来使得Service或Method不被代办：
[NonAspect]
public interface ICustomService
{
void Call();
}
同时支撑全局疏忽设置，亦支撑通配符：
services.AddAspectCore(config =>
{
//App1定名空间下的Service不会被代办
config.NonAspectOptions.AddNamespace("App1");
//末了一级为App1的定名空间下的Service不会被代办
config.NonAspectOptions.AddNamespace("*.App1");
//ICustomService接口不会被代办
config.NonAspectOptions.AddService("ICustomService");
//后缀为Service的接口和类不会被代办
config.NonAspectOptions.AddService("*Service");
//定名为Query的要领不会被代办
config.NonAspectOptions.AddMethod("Query");
//后缀为Query的要领不会被代办
config.NonAspectOptions.AddMethod("*Query");
});
拦截器中的依靠注入。在拦截器中支撑属性注入，组织器注入和效劳定位器形式。
属性注入，在拦截器中具有public get and set权限的属性标记[AspectCore.Abstractions.FromServices](区分于Microsoft.AspNetCore.Mvc.FromServices)特征，即可自动注入该属性，如：
public class CustomInterceptorAttribute : InterceptorAttribute
{
[AspectCore.Abstractions.FromServices]
public ILogger<CustomInterceptorAttribute> Logger { get; set; }
public override Task Invoke(AspectContext context, AspectDelegate next)
{
Logger.LogInformation("call interceptor");
return next(context);
}
}
组织器注入须要使拦截器作为Service，除全局拦截器外，仍可运用ServiceInterceptor使拦截器从DI中激活：
public interface ICustomService
{
[ServiceInterceptor(typeof(CustomInterceptorAttribute))]
void Call();
}
效劳定位器形式。拦截器上下文AspectContext能够猎取当前Scoped的ServiceProvider：
public class CustomInterceptorAttribute : InterceptorAttribute
{
public override Task Invoke(AspectContext context, AspectDelegate next)
{
var logger = context.ServiceProvider.GetService<ILogger<CustomInterceptorAttribute>>();
logger.LogInformation("call interceptor");
return next(context);
}
}
运用Autofac和AspectCore。AspectCore原生支撑集成Autofac，我们须要装置下面两个nuget packages：
PM> Install-Package Autofac.Extensions.DependencyInjection PM> Install-Package AspectCore.Extensions.Autofac
AspectCore供应RegisterAspectCore扩大要领在Autofac的Container中注册动态代办须要的效劳，并供应AsInterfacesProxy和AsClassProxy扩大要领启用interface和class的代办。修正ConfigureServices要领为：
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddMvc();
var container = new ContainerBuilder();
container.RegisterAspectCore();
container.Populate(services);
container.RegisterType<CustomService>().As<ICustomService>().InstancePerDependency().AsInterfacesProxy();
return new AutofacServiceProvider(container.Build());
}
以上就是浅谈AspectCore_实用技巧的细致内容，更多请关注ki4网别的相干文章！
