c# - Angular 6 .Net core 2.2 App 中的 Cors 错误

Question

我开发了 .Net Core MVC (angular) 应用程序和 .net core Api 应用程序

在这两个应用程序中，我都在 Web 应用程序和 api 中启用了 CORS

.Net核心

 services.AddCors(options =>
        {
            options.AddPolicy("CorsPolicy",
                builder => builder.AllowAnyOrigin()
                .AllowAnyMethod()
                .AllowAnyHeader()
                .AllowCredentials());
        });
// in Configure

    app.UseCors("CorsPolicy");

Angular

对于所有的 Get 和 Post 添加像下面这样的标题

get(url: string, options?: any) {
    let headers = new Headers();
    headers.append('Content-Type', 'application/x-www-form-urlencoded');
    headers.append('Access-Control-Allow-Origin', '*');
    headers.append('Accept', 'applcation/ json');
    options = { headers: headers };
    const _url = this.webapiurl + url;
    return this.http.get(_url, options);    
  }

仍然面临 CORS 错误

Access to XMLHttpRequest at 'http://etestservice.qa.com:5003/QA/api/test/GetDetails?email=abc@gmail.com' from origin 'http://etestweb.qa.com::5002' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource

Answer 1

在startup.cs文件中

public void ConfigureServices(IServiceCollection services)
{
        services.AddMvc();

        // app settings configuration.
        services.AddCors(options =>
        {
            // this defines a CORS policy called "default"
            options.AddPolicy("AllowSpecificOrigin", policy =>
            {
                var corsUrlSection = Configuration.GetSection("AllowedOrigins");
                var corsUrls = corsUrlSection.Get<string[]>();
                policy.WithOrigins(corsUrls)
                    .AllowAnyHeader()
                    .WithExposedHeaders("X-Pagination") // add any customer header if we are planning to send any 
                    .AllowAnyMethod();
            });
        });

}



public void Configure(IApplicationBuilder app, IHostingEnvironment environment, ILoggerFactory loggerFactory)
{

        app.UseExceptionMiddleware();

        // Use HTTPS Redirection Middleware to redirect HTTP requests to HTTPS.
        app.UseHttpsRedirection();

        app.UseCors("AllowSpecificOrigin");

        app.UseMvc();

}

在 API 中，

[EnableCors("AllowSpecificOrigin")]
public class Controller
{
   // code...
}

中间件组件的顺序是必须的。所以检查一下。我在这里附上了我的项目代码。