const string policyName = "CorsPolicy";
//添加跨域配置，加载进来，启用的话需要使用Configure
services.AddCors(options =>
    options.AddPolicy(policyName, builder =>
    {
        builder
            .AllowAnyHeader()
            .AllowAnyOrigin()
            .AllowAnyMethod();
        //builder.AllowCredentials(); 该方法不能和AllowAnyOrigin 同时使用，否则会触发异常：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
    })
);

const string policyName = "CorsPolicy";
//支持跨域
app.UseCors(policyName);