Asp.net Vnext Filters

ASP.NET MVC 提供Filters(筛选器)之前或之后调用操作方法执行筛选逻辑，和AOP面向切面编程一样。

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  本文已经同步到《Asp.net Vnext 系列教程 》中]

本章主要介绍AuthorizeAttribute
Authorize 属性，可以对控制器操做的声明性的授权检查。 现。
实例代码

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启动类

 services.ConfigureAuthorization(options =>
            {
           //添加策略
                options.AddPolicy("Api-Manager", policy =>
                {  //添加认证方案的名字
                    policy.ActiveAuthenticationSchemes.Add("Api");
                    //创建认证策略Claim
                    policy.RequireClaim("Permission", "CanViewPage");
                });


            });

  public void Configure(IApplicationBuilder app)
        {

            app.UseMiddleware<AuthorizeBasicMiddleware>("Api");
            //添加中间件

        }

中间件

 public class AuthorizeBasicMiddleware : AuthenticationMiddleware<BasicOptions>
    {
        public AuthorizeBasicMiddleware(    RequestDelegate next,  IOptions<BasicOptions> options, string authScheme) : 
                                                                                                             //这里必需是"Api"
          base(next, options,  new ConfigureOptions<BasicOptions>(o => o.AuthenticationScheme = authScheme) { Name = authScheme })
        {
        }

        protected override AuthenticationHandler<BasicOptions> CreateHandler()
        {
            //new 一个认证处理
            return new BasicAuthenticationHandler();
        }
    }

认证处理类

  public class BasicAuthenticationHandler : AuthenticationHandler<BasicOptions>
    {
        protected override void ApplyResponseChallenge()
        {

            //验证失败进行跳转
           // this.Response.Redirect("http://baidu.com");
         
        }

        protected override void ApplyResponseGrant()
        {
            //验证失败清除Cookies
            //this.Response.Cookies.Delete("11");

            }

        protected override AuthenticationTicket AuthenticateCore()
        {
            var principal = new ClaimsPrincipal();
            //添加Claim
            principal.AddIdentity(new ClaimsIdentity(
                new Claim[] {
                    new Claim("Permission", "CanViewPage"),
                   
                },
                Options.AuthenticationScheme));
            //返回一个票据
            return new AuthenticationTicket(principal, new AuthenticationProperties(), Options.AuthenticationScheme);
        }
    }

控制器

   public class AuthorizeUserController : Controller
    {
                 //策略名表示应用的策略
        [Authorize("Api-Manager")]
        public string ApiManagers()
        {
            return "Hello World!";
        }

这个时候我们修改一认证处理类

  public class BasicAuthenticationHandler : AuthenticationHandler<BasicOptions>
    {
        protected override void ApplyResponseChallenge()
        {

            //验证失败进行跳转
           this.Response.Redirect("http://baidu.com");
         
        }

        protected override void ApplyResponseGrant()
        {
            //验证失败清除Cookies
            //this.Response.Cookies.Delete("11");

            }

        protected override AuthenticationTicket AuthenticateCore()
        {
            var principal = new ClaimsPrincipal();
            //添加Claim
            principal.AddIdentity(new ClaimsIdentity(
                new Claim[] {
                    new Claim("Permission", "CanViewPage1"),
                  
                },
                Options.AuthenticationScheme));
            //返回一个票据
            return new AuthenticationTicket(principal, new AuthenticationProperties(), Options.AuthenticationScheme);
        }
    }

在认证处理类没有找到相同的Claim,导致认证失败，跳转百度。

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简单介绍过滤器,估计大家都会
IExceptionFilter 异常过滤器
IActionFilter 动作过滤器
IResultFilter 结果过滤器
AuthorizationFilterAttribute 认证过滤器
启动类中注册全局过滤器

  services.Configure<MvcOptions>(options =>
            {
                options.Filters.Add(new GlobalExceptionFilter());
                options.Filters.Add(new GlobalActionFilter());
                options.Filters.Add(new GlobalResultFilter());
                options.Filters.Add(new GlobalAuthorizationFilter());

            });

Asp.net vnext 文档
http://mvc.readthedocs.org/en/latest/index.html