HTTP拦截器显示多条消息问题

Question

在我的项目中(.net Core2.2+ angular 8).For显示一个错误HttpInterceptor，它工作得很完美，但对于多个消息，它也可以工作，但不能显示正确的错误消息。我得到了一些类似的东西：

[object Object] One or more validation errors occurred. 400 0HLRCTBS664E8:00000002

我的拦截器看起来像这样：

@Injectable()
export class ErrorInterceptor implements HttpInterceptor {
    intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        return next.handle(req).pipe(
            catchError(error => {
                if (error instanceof HttpErrorResponse) {
                    if (error.status === 401) {
                        return throwError(error.statusText);
                    }
                    const applicationError = error.headers.get('Application-Error');
                    if (applicationError) {
                        console.error(applicationError);
                        return throwError(applicationError);
                    }
                    const serverError = error.error;
                    let modalStateErrors = '';
                    if (serverError && typeof serverError === 'object') {
                        for (const key in serverError) {
                            if (serverError[key]) {
                                modalStateErrors += serverError[key] + '\n';
                            }
                        }
                    }
                    return throwError(modalStateErrors || serverError || 'Server Error');
                }
            })
        )
    }
}

export const ErrorInterceptorProvide = {
    provide: HTTP_INTERCEPTORS,
    useClass: ErrorInterceptor,
    multi: true
}

我使用的dto类：

    [Required(ErrorMessage = "username is required")]
    public string Username { get; set; }

    [Required(ErrorMessage = "password is required")]
    [StringLength(20, MinimumLength = 6, ErrorMessage = "Password should be between 6 and 20 
    characters")]
    public string Password { get; set; }

我的Startup类如下所示：

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler(builder =>
            {
                builder.Run(async context =>
                {
                    context.Response.StatusCode = (int) HttpStatusCode.InternalServerError;

                    var error = context.Features.Get<IExceptionHandlerFeature>();
                    if (error != null)
                    {
                        context.Response.AddApplicationError(error.Error.Message);
                        await context.Response.WriteAsync(error.Error.Message);
                    }
                });
            });                
        }


        app.UseCors(x => x.AllowAnyOrigin().AllowAnyMethod().AllowAnyHeader());
        app.UseAuthentication();

        app.UseMvc();

    }
 }

应用程序错误扩展方法：

    public static class Extensions
    {
        public static void AddApplicationError(this HttpResponse response, string message)
        {
            response.Headers.Add("Application-Error", message);
            response.Headers.Add("Access-Control-Expose-Headers", "Application-Error");
            response.Headers.Add("Access-Control-Allow-Origin", "*");
        }
    }

Answer 1

在你的应用编程接口中，你似乎遇到了automatic 400 responses的问题。

避免它的最好方法是抑制这个错误。

若要禁用自动400行为，请将SuppressModelStateInvalidFilter属性设置为true。在Startup.ConfigureServices中添加以下突出显示的代码：

这是本文中包含的代码：

services.AddMvc()

.SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
.ConfigureApiBehaviorOptions(options =>
{
    options.SuppressConsumesConstraintForFormFileParameters = true;
    options.SuppressInferBindingSourcesForParameters = true;
    options.SuppressModelStateInvalidFilter = true;
    options.SuppressMapClientErrors = true;
    options.ClientErrorMapping[404].Link =
        "https://httpstatuses.com/404";
});

微软的recommended way in github, is here