/// <summary>
        /// Display an RSS feed.
        /// </summary>
        /// <param name="url">The URL of the RSS feed.</param>
        public void Process(Uri url)
        {
            RSS rss = new RSS();

            rss.Load(url);
            Console.WriteLine(rss.ToString());
        }
        /// <summary>
        /// RSSを取得
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void BtnGet_Click(object sender, EventArgs e)
        {
            var url   = "https://blogs.windows.com/feed/";
            var rsscl = new RSSClient();
            var xml   = await rsscl.Open(url);

            var rss = RSS.Load(xml);

            _rss = rss;
            var arr = new ArrayAdapter <RSSItem>(this, Android.Resource.Layout.SimpleListItem1, rss.channel.Items);

            lv.Adapter    = arr;
            lv.ItemClick += Lv_ItemClick;
        }