Asp.Net Core WebApi5解决跨域问题

Access to XMLHttpRequest at 'http://localhost:60540/api/Orders' from origin 'http://localhost:63343' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

一般来说前后端分离都会遇到跨域问题，WebApi也不例外咯，然后今天做作业的时候遇到了

在百度上找了一番，都是老版本的解决方案，没有我使用的这个webapi5，文件结构是这样的。

最后还是去翻官方文档找到了解决方案。

public void ConfigureServices(IServiceCollection services)
{
    services.AddCors(options =>
    {
        options.AddPolicy(MyAllowSpecificOrigins,
                          builder =>
                          {
                              builder.WithOrigins("http://example.com",
                                                  "http://www.contoso.com")
                                                  .AllowAnyHeader()
                                                  .AllowAnyMethod();
                          });
    });

    services.AddControllers();
}

https://docs.microsoft.com/zh-cn/aspnet/core/security/cors?view=aspnetcore-5.0#cors-with-named-policy-and-middleware