Cors 在启用OWIN的应用程序中生成令牌期间，访问控制允许原点错误

我正在使用Angular 8应用程序中的C#Web API+CORS+Owin。生成令牌时出现以下错误。我看了variuos的文章，但我无法解决这个问题

从源代码访问“”处的XMLHttpRequest “”已被CORS策略阻止：否 “Access Control Allow Origin”标头出现在请求的服务器上 资源

Global.asax.cs

protected void Application_Start()
        {
           // AreaRegistration.RegisterAllAreas();
            GlobalConfiguration.Configure(WebApiConfig.Register);   
        }

        protected void Application_BeginRequest()
        {                
            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
            {                    
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "http://localhost:4200");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, PUT, DELETE, POST, OPTIONS");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept, Authorization, No-Auth");
                HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000");
                HttpContext.Current.Response.End();
            }
        }

public void Configuration(IAppBuilder app)
        {            
            app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);
            var myProvider = new AuthorizationServerProvider();
            OAuthAuthorizationServerOptions options = new OAuthAuthorizationServerOptions
            {
                AllowInsecureHttp = true,
                TokenEndpointPath = new PathString("/Token"),
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
                Provider = myProvider
            };
            app.UseOAuthAuthorizationServer(options);

            app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());

        }

public static void Register(HttpConfiguration config)
        {            
            // Web API routes
            config.MapHttpAttributeRoutes();
            config.Filters.Add(new LoggingFilterAttribute());
            config.Filters.Add(new CustomExceptionFilterAttribute());

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
            config.Formatters.Remove(config.Formatters.XmlFormatter);

            GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings =
            new JsonSerializerSettings
            {
                DateFormatHandling = DateFormatHandling.IsoDateFormat,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
            };
        }

Startup.cs

protected void Application_Start()
        {
           // AreaRegistration.RegisterAllAreas();
            GlobalConfiguration.Configure(WebApiConfig.Register);   
        }

        protected void Application_BeginRequest()
        {                
            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
            {                    
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "http://localhost:4200");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, PUT, DELETE, POST, OPTIONS");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept, Authorization, No-Auth");
                HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000");
                HttpContext.Current.Response.End();
            }
        }

public void Configuration(IAppBuilder app)
        {            
            app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);
            var myProvider = new AuthorizationServerProvider();
            OAuthAuthorizationServerOptions options = new OAuthAuthorizationServerOptions
            {
                AllowInsecureHttp = true,
                TokenEndpointPath = new PathString("/Token"),
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
                Provider = myProvider
            };
            app.UseOAuthAuthorizationServer(options);

            app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());

        }

public static void Register(HttpConfiguration config)
        {            
            // Web API routes
            config.MapHttpAttributeRoutes();
            config.Filters.Add(new LoggingFilterAttribute());
            config.Filters.Add(new CustomExceptionFilterAttribute());

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
            config.Formatters.Remove(config.Formatters.XmlFormatter);

            GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings =
            new JsonSerializerSettings
            {
                DateFormatHandling = DateFormatHandling.IsoDateFormat,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
            };
        }

WebApiConfig.cs

protected void Application_Start()
        {
           // AreaRegistration.RegisterAllAreas();
            GlobalConfiguration.Configure(WebApiConfig.Register);   
        }

        protected void Application_BeginRequest()
        {                
            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
            {                    
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "http://localhost:4200");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, PUT, DELETE, POST, OPTIONS");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept, Authorization, No-Auth");
                HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000");
                HttpContext.Current.Response.End();
            }
        }

public void Configuration(IAppBuilder app)
        {            
            app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);
            var myProvider = new AuthorizationServerProvider();
            OAuthAuthorizationServerOptions options = new OAuthAuthorizationServerOptions
            {
                AllowInsecureHttp = true,
                TokenEndpointPath = new PathString("/Token"),
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
                Provider = myProvider
            };
            app.UseOAuthAuthorizationServer(options);

            app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());

        }

public static void Register(HttpConfiguration config)
        {            
            // Web API routes
            config.MapHttpAttributeRoutes();
            config.Filters.Add(new LoggingFilterAttribute());
            config.Filters.Add(new CustomExceptionFilterAttribute());

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
            config.Formatters.Remove(config.Formatters.XmlFormatter);

            GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings =
            new JsonSerializerSettings
            {
                DateFormatHandling = DateFormatHandling.IsoDateFormat,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
            };
        }

web.config

<system.webServer>
    <modules>
      <remove name="FormsAuthentication" />
    </modules>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
    <directoryBrowse enabled="true" />
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="30000000" />
      </requestFiltering>
    </security>    
  </system.webServer>

我的解决方案中已添加以下引用：-

• Microsoft.AspNet.Identity.Owin
• Microsoft.Owin Microsoft.Owin.Cors
• Microsoft.Owin.Security
• Microsoft.Owin.Security.Cookies
• Microsoft.Owin.Security.OAuth

---

请帮助我解决此问题。

请通过在web.config文件中添加来尝试从应用程序\u Begin请求中删除此项，我认为这可能对您有用

 <system.webServer>
      <httpProtocol>
        <customHeaders>
          <add name="Access-Control-Allow-Origin" value="*" />
          <add name="Access-Control-Allow-Headers" value="Content-Type" />
          <add name="Access-Control-Allow-Methods" value="GET,POST,PUT,DELETE,OPTIONS" />
         <add name="Access-Control-Allow-Credentials" value="true" />
        </customHeaders>
      </httpProtocol>
  </system.webServer>

---

我也经历过同样的事情，我通过这样做解决了问题。

这样做会给我以下错误：-“对飞行前请求的响应未通过访问控制检查：它没有HTTP ok状态。”Hi@simpleuser，现在您遇到了其他错误。