网站开发需要什么专业的人才,90设计手机站,有哪些h5做的网站,建模网站熟悉ASP.NET架构的开发者一定对于HTTP Modules与HTTP Handlers不陌生。两者的作用主要是对网络请求执行特定的处理工作。而在.NET Core中#xff0c;它们都被Middleware(中件间)取代了。之前的Http Modules和HTTP Handlers是如下图般处理请求的#xff1a;现在变成了这样它们都被Middleware(中件间)取代了。之前的Http Modules和HTTP Handlers是如下图般处理请求的现在变成了这样一言概括之Middleware完成了HTTP Modules与HTTP Handlers的原有工作但又不是简单的化二为一的减法作用。Middleware减去的其实是与原来ASP.NET中重要的基础——应用程序生命周期事件(application life cycle event)的绑定。HTTP Modules在初始化时就需要针对HttpApplication的事件作绑定处理这样当HttpApplication的各项事件被触发时已绑定的相应处理程序才会按照预期的那样被执行。public class HelloWorldModule : IHttpModule{ public HelloWorldModule() {} public String ModuleName{ get { return HelloWorldModule; }} // In the Init function, register for HttpApplication // events by adding your handlers.public void Init(HttpApplication application) {application.BeginRequest (new EventHandler(this.Application_BeginRequest));application.EndRequest (new EventHandler(this.Application_EndRequest));} private void Application_BeginRequest(Object source, EventArgs e) { // Create HttpApplication and HttpContext objects to access// request and response properties.HttpApplication application (HttpApplication)source;HttpContext context application.Context;context.Response.Write(h1font colorredHelloWorldModule: Beginning of Request/font/h1hr);} private void Application_EndRequest(Object source, EventArgs e) {HttpApplication application (HttpApplication)source;HttpContext context application.Context;context.Response.Write(hrh1font colorredHelloWorldModule: End of Request/font/h1);} public void Dispose() {}
}然后你还需要在web.config配置文件注册这个HTTP Module。configurationsystem.webhttpModulesadd nameHelloWorldModule typeHelloWorldModule//httpModules/system.web/configuration如果是用Middleware的话事情就变得很简单了。抛弃IHttpModule接口及HttpModule实现类不用再关心HttpApplication的任何事件还有烦人的web.config配置。直接在代码中以最简洁的方式完成工作。 public void Configure(IApplicationBuilder app, IHostingEnvironment env){app.Use(async(context, next) { await context.Response.WriteAsync(Beginning of Request\n); await next.Invoke(); await context.Response.WriteAsync(End of Request\n);});app.Run(async (context) { await context.Response.WriteAsync(Hello World!\n);});
}相似的对于HTTP Handlers虽然不用取消对HttpApplication事件的依赖但以两者的代码实现方式作比较Middleware亳无疑问胜出一筹。public class HelloWorldHandler : IHttpHandler{ public HelloWorldHandler() {} public void ProcessRequest(HttpContext context) {HttpRequest Request context.Request;HttpResponse Response context.Response; // This handler is called whenever a file ending // in .sample is requested. A file with that extension// does not need to exist.Response.Write(html);Response.Write(body);Response.Write(h1Hello from a synchronous custom HTTP handler./h1);Response.Write(/body);Response.Write(/html);} public bool IsReusable{ // To enable pooling, return true here.// This keeps the handler in memory.get { return false; }}
}仍需要在web.config文件中注册HTTP handler。configurationsystem.webhttpHandlersadd verb* path*.sample typeHelloWorldHandler//httpHandlers/system.web/configuration换作Middleware的写法private static void HandleSample(IApplicationBuilder app){app.Run(async context { await context.Response.WriteAsync(Hello Sample);});
}// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.public void Configure(IApplicationBuilder app, IHostingEnvironment env){app.MapWhen(context context.Request.Path.Value.EndsWith(sample), HandleSample);
}总结下使用Middleware的优点没有对HttpApplication的依赖没有对IHttpModule与IHttpHandler接口的依赖无需在web.config文件中添加各种配置代码简洁最后需要补充Middleware与HTTP Modules的一点差异。各Middleware中处理请求与响应的顺序是刚好相反的越早处理请求的Middleware越晚处理响应。而HTTP Modules中处理请求与响应的顺序则保持一致因为每个HTTP Module请求与响应事件的绑定都是在同一阶段完成的。
