.net webAPI跨域问题解决方案

因为最近有项目用到.net Core 3.1  webAPI，接口有跨域问题，网上百度了一些都是用配置Cors来解决的

现在我记录一下，在解决问题过程中出现的问题

在Startup.ConfigureServices中，添加服务

注意：.net Core 3.1版本  Cors配置不能同时启用  AllowAnyOrigin()  .AllowAnyMethod()  .AllowAnyHeader()  .AllowCredentials()

否则报错 System.InvalidOperationException
  HResult=0x80131509
  Message=The CORS protocol does not allow specifying a wildcard (any) origin and credentials at the same time. Configure the CORS policy by listing individual origins if credentials needs to be supported.
  Source=Microsoft.AspNetCore.Cors 

//添加cors 服务 配置跨域处理   
            services.AddCors(options =>
            {
                options.AddPolicy("any", builder =>
                {
                    builder.WithMethods("GET", "POST", "HEAD", "PUT", "DELETE", "OPTIONS")
                    //.AllowCredentials()//指定处理cookie
                .AllowAnyOrigin(); //允许任何来源的主机访问
                });
            });

在Startup.Configure中，添加配置

注意： app.UseCors("any"); 要写在app.UseAuthorization(); 后面，否则会报错。

Configure your application startup by adding app.UseCors() inside the call to Configure(..) in the application startup code. The call to app.UseAuthorization() must appear between app.UseRouting() and app.UseEndpoints(...).VM310:3 GET http://链接 net::ERR_CONNECTION_REFUSED

app.UseRouting();
            app.UseAuthorization();
            app.UseAuthentication();
            //配置Cors
            app.UseCors("any");
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers().RequireCors("any");
            });

这些配置完成就能解决跨域问题了，欢迎大家指出错误或评论区讨论问题