Cross-Origin Request Blocked：（原因：CORS 请求未成功）

Question

我正在开发一个全栈应用程序，后端使用 ASP.NET core 5.0 Web Api，前端使用 Angular 12。

向后端发送 http post 请求时，我收到与 CORS 策略相关的错误。

错误是：

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://localhost:5001/api/v1/user/login. (Reason: CORS request did not succeed).

我看了这个link： https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS/Errors/CORSDidNotSucceed，但它没有给我足够的信息来提出解决方案

我认为我的问题可能与第一个要点有关：

Trying to access an https resource that has an invalid certificate will cause this error

因为我的前端使用的是http协议，我的后端使用的是https协议。

什么是有效证书？

我的网络浏览器中也没有安装广告拦截器，所以我想不出还有什么可以尝试的，因为我相信我在以下代码中启用了 CORS。

有什么问题吗？我可能缺少某种配置或其他东西？

代码示例

后端

startup.cs

// startup.cs
using MyApi.Installers;

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace MyApi
{
    public class Startup
    {

        public Startup(IConfiguration configuration) => Configuration = configuration;

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // CORS CONFIGURED HERE           
            services.AddCors(options =>
            {
                options.AddPolicy("CorsApi",
                    builder => builder.WithOrigins("http://localhost:4200")
                .AllowAnyHeader()
                .AllowAnyMethod());
            });

            // This is an extension method that installs swagger, jwt, services, etc...
            // I can add those also if need be
            services.InstallServicesInAssembly(Configuration);
        }

        // 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();
            }

            SwaggerOptions swaggerOptions = new SwaggerOptions();
            Configuration.GetSection(nameof(SwaggerOptions)).Bind(swaggerOptions);

            app.UseSwagger(options => options.RouteTemplate = swaggerOptions.JsonRoute);
            app.UseSwaggerUI(options =>
            {
                options.SwaggerEndpoint(swaggerOptions.UiEndpoint, swaggerOptions.Description);
                options.RoutePrefix = System.String.Empty;
            });

            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            // CORS ENABLED HERE
            app.UseCors("CorsApi");

            app.UseAuthorization();

            app.UseEndpoints(endpoints => endpoints.MapControllers());
        }
    }
}

UserController.cs -> 登录功能

// UserController.cs -> Login function
        [HttpPost(ApiRoutes.User.Login)]
        public IActionResult Login([FromBody] UserLoginRequest request)
        {
            if (!ModelState.IsValid)
            {

                return BadRequest();
            }

            // Validates users credentials
            if (!_userService.IsValidUserCredentials(request.Email, request.Password))
            {
                return Unauthorized();
            }

            return Ok(});
        }

前端

auth-service.ts

// auth.service.ts
export class AuthService {

  private readonly baseUrl = 'https://localhost:5001/api/v1';

  // Adds CORS header to the request?
  private httpOptions = { headers: new HttpHeaders({ 'Content-Type':'application/json','Access-Control-Allow-Origins':'*'})};

  constructor(
    private http: HttpClient
  ) { }

  login(email: string, password: string): Observable<any> {
    let postData = new FormData();
    postData.append('email', email);
    postData.append('password', password);

    return this.http.post<any>(`${this.baseUrl}/user/login`, postData, this.httpOptions);
  }
}

login.component.ts

// login.component.ts
export class LoginComponent implements OnInit {
  loginForm = this.fb.group({
    email: ['', Validators.compose([Validators.email, Validators.required])],
    password: ['', Validators.required]
  });

  constructor(
    private authService: AuthService,
    private router: Router,
    private fb: FormBuilder,
  ) { }

  ngOnInit(): void { }

  get f() {
    return this.loginForm.controls;
  }

  login(form: FormGroup): void {
    // These output in console window
    console.log(this.f.email.value);
    console.log(this.f.password.value);

    // Error here
    this.authService.login(this.f.email.value, this.f.password.value).subscribe(
      response => {
        // This does not get output
        console.log(response);
        //this.router.navigate(['/home']);
      },
      error => console.log(error)
    );
  }

}

我尽量使代码尽可能简单。

编辑：忘了说我也启用了这个：

Answer 1

尝试将 UseCors 放在 UseRouting 和 UseAuthorization 之间

 app.UseRouting();
 app.UseCors("CorsApi");
 app.UseAuthorization();

为 AddCors 尝试此语法

services.AddCors(o => o.AddPolicy("CorsApi", builder =>
            {
                builder.WithOrigins("http://localhost:4200")
                       .AllowAnyMethod()
                       .AllowAnyHeader();
            }));

也许如果它仍然不起作用，也将其删除

'Access-Control-Allow-Origins':'*'

Answer 2

所以，我不一定能解释为什么这解决了我的问题，但确实...

在 chrome 我还去了：chrome://settings/security -> 管理证书 -> 删除本地主机证书。

然后在 Visual Studio 终端运行命令：dotnet dev-certs https --trust

经过以下作品

在Startup.cs中：

readonly string MyAllowSpecificOrigins = "_myAllowSpecificOrigins";

在 startup.cs -> ConfigureServices:

services.AddCors(options =>
{
    options.AddPolicy(MyAllowSpecificOrigins,
        builder => builder.AllowAnyOrigin()
                           .AllowAnyMethod()
                           .AllowAnyHeader()
        );
});

在Startup.cs -> 配置：

app.UseRouting();

app.UseAuthorization();
app.UseAuthentication();
// ... 
// UseCors must be between routing and endpoints
app.UseCors(MyAllowSpecificOrigins);
// ...
app.UseEndpoints(endpoints =>
{
    endpoints.MapControllers();
});

Cross-Origin Request Blocked：（原因：CORS 请求未成功）

Cross-Origin Request Blocked: (Reason: CORS request did not succeed)

c#

ssl

ssl-certificate

asp.net-core

angular

代码示例