Asp.net OAuth2.0 跨域设置（可指定域名）

第一步：Startup添加如下代码

 第二步：功能实现

 /// <summary>
    /// 跨域配置
    /// </summary>
    public class CorsOriginsConfig
    {
        /// <summary>
        /// 设置
        /// </summary>
        public static void Set(IAppBuilder app)
        {
            //不允许跨域
            if (PublicVars.CorsOrigins == "")
            {
                return;
            }
            //允许所有域
            if (PublicVars.CorsOrigins == "*")
            {
                app.UseCors(CorsOptions.AllowAll);//信任所有站点
                return;
            }
            //指定域
            string[] arrOrigin = PublicVars.CorsOrigins.Split(new char[] { '|' }, StringSplitOptions.RemoveEmptyEntries);
            app.UseCors(new CorsOptions
            {
                PolicyProvider = new CorsPolicyProvider
                {
                    PolicyResolver = context =>
                    {
                        var policy = new CorsPolicy();
                        foreach (var item in arrOrigin)
                        {
                            policy.Origins.Add(item);
                        }
                        return Task.FromResult(policy);
                    }
                }
            });
        }
    }