asp.net mvc core管道及拦截器的理解
这篇文章主要给大家介绍了关于asp.net mvc core管道及拦截器的相关资料,文中通过示例代码介绍的非常详细,对大家学习或者使用asp.net mvc core具有一定的参考学习价值,需要的朋友们下面来一起学习学习吧
今天来看一下asp.net core的执行管道。先看下官方说明:
从上图可以抛光,asp.net core的执行顺序是,当收到一个请求后,request请求会先经过已注册的中间件,然后会进入到mvc的拦截器管道:
进入mvc管道后,根据以上顺序执行过滤校正。
OK,根据以上说明下面我们新建一个MVC的演示,将执行方式切换为控台运行:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | // This method gets called by the runtime. Use this method to add services to the container. public void ConfigureServices(IServiceCollection services) { services.AddControllersWithViews(config=> { Console.WriteLine( "execute C" ); //config.Filters.Add(new AsyncAuthorizationFilter()); config.Filters.Add( new AuthorizationFilter()); config.Filters.Add( new ResourceFilter()); //config.Filters.Add(new AsyncResourceFilter()); config.Filters.Add( new ActionFilter()); //config.Filters.Add(new AsyncActionFilter()); config.Filters.Add( new ResultFilter()); //config.Filters.Add(new AsyncResultFilter()); config.Filters.Add( new ExceptionFilter()); //config.Filters.Add(new AsyncExceptionFilter()); Console.WriteLine( "execute D" ); }); services.AddSession(config=> { Console.WriteLine( "execute E" ); }); } // This method gets called by the runtime. Use this method to configure the HTTP request pipeline. public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } else { app.UseExceptionHandler( "/Home/Error" ); } app.UseStaticFiles(); app.UseRouting(); app.UseAuthorization(); app.Use(async (context, next) => { Console.WriteLine( "execute F" ); await context.Response.WriteAsync( "hello world" ); Console.WriteLine( "execute G" ); }); //app.UseSession(); app.UseEndpoints(endpoints => { Console.WriteLine( "execute A" ); endpoints.MapControllerRoute( name: "default" , pattern: "{controller=Home}/{action=Index}/{id?}" ); Console.WriteLine( "execute B" ); }); } |
执行结果:
不多做解释,从从这里我们可以抛光符合官方说明文档。
看完中间件执行顺序,下面我们来了解下mvc拦截器的使用与执行顺序。
根据mvc filter管道执行顺序,我们分别来看下用法:
1)AuthorizationFilter:该拦截器是优先级最高的,当请求进入mvc后,首先会被AuthorizationFilter验证是否有权限访问,无权限则跳出。
同步用法:
1 2 3 4 5 6 7 | public class AuthorizationFilter: IAuthorizationFilter { public void OnAuthorization(AuthorizationFilterContext context) { context.HttpContext.Response.WriteAsync( "authorization filter \r" ); } } |
异步用法:
1 2 3 4 5 6 7 | public class AsyncAuthorizationFilter: IAsyncAuthorizationFilter { public async Task OnAuthorizationAsync(AuthorizationFilterContext context) { await context.HttpContext.Response.WriteAsync($ "async authorization filter in \r" ); } } |
2)ResourceFilter:该拦截器是作为第二道拦截器,
OnResourceExecuting在模型绑定之前运行代码。OnResourceExecuted在管道的其余阶段完成之后运行代码。
同步用法:
1 2 3 4 5 6 7 8 9 10 11 | public class ResourceFilter: IResourceFilter { public void OnResourceExecuting(ResourceExecutingContext context) { context.HttpContext.Response.WriteAsync($ "resource executing\r" ); } public void OnResourceExecuted(ResourceExecutedContext context) { context.HttpContext.Response.WriteAsync($ "resource executed \r" ); } } |
异步用法:
1 2 3 4 5 6 7 8 9 | public class AsyncResourceFilter: IAsyncResourceFilter { public async Task OnResourceExecutionAsync(ResourceExecutingContext context, ResourceExecutionDelegate next) { await context.HttpContext.Response.WriteAsync($ " async resource filter in. \r\n" ); await next(); await context.HttpContext.Response.WriteAsync($ "async resource filter out. \r\n" ); } } |
3)ActionFilter:在调用操作方法之前和之后立即运行代码;可以更改传递到操作中的参数;可以更改从操作返回的结果。
同步用法:
1 2 3 4 5 6 7 8 9 10 11 12 | public class ActionFilter: IActionFilter { public void OnActionExecuting(ActionExecutingContext context) { context.HttpContext.Response.WriteAsync($ "action executing \r" ); } public void OnActionExecuted(ActionExecutedContext context) { context.HttpContext.Response.WriteAsync($ "action executed . \r" ); } } |
异步用法:
1 2 3 4 5 6 | public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next) { await context.HttpContext.Response.WriteAsync($ "async action execution in. \r\n" ); await next(); await context.HttpContext.Response.WriteAsync($ "async action execution out. \r\n" ); } |
4)OnException:在向响应正文写入任何内容之前,对声明处理的异常应用变量策略。
同步用法:
1 2 3 4 5 6 7 | public class ExceptionFilter: IExceptionFilter { public void OnException(ExceptionContext context) { context.HttpContext.Response.WriteAsync($ "exception \r" ); } } |
异步用法:
1 2 3 4 5 6 7 8 | public class AsyncExceptionFilter: IAsyncExceptionFilter { public Task OnExceptionAsync(ExceptionContext context) { context.HttpContext.Response.WriteAsync($ "exception async \r" ); return Task.CompletedTask; } } |
5)ResultFilter:在执行操作结果之前和之后立即运行代码;仅当操作方法成功执行时,其才会运行。 可以设置格式化返回结果:
同步操作:
1 2 3 4 5 6 7 8 9 10 11 | public class ResultFilter: IResultFilter { public void OnResultExecuting(ResultExecutingContext context) { context.HttpContext.Response.WriteAsync($ "result executing\r" ); } public void OnResultExecuted(ResultExecutedContext context) { context.HttpContext.Response.WriteAsync($ "result executed \r" ); } } |
异步用法:
1 2 3 4 5 6 7 8 9 | public class AsyncResultFilter: IAsyncResultFilter { public async Task OnResultExecutionAsync(ResultExecutingContext context, ResultExecutionDelegate next) { await context.HttpContext.Response.WriteAsync($ "result execution async in \r" ); await next(); await context.HttpContext.Response.WriteAsync($ "result execution async out. \r" ); } } |
注册方式我们就是用分区注册,已经在上面说明,不再多做表述,下面我们看下运行情况(页面输出):
定义一个异常看下结果:
1 2 3 4 | public IActionResult Privacy() { throw new Exception( "error" ); } |
ok,目标达成,不多说了,下次再看拦截器具体实现。
参考文档:ASP.NET Core 中的筛选器
总结
到此这篇关于asp.net mvc core管道及拦截器的文章就介绍到这了