请各位老师同仁帮忙看一下代码解决思路

请各位老师同仁帮忙看一下代码
代码如下：
public partial class MainPage : PhoneApplicationPage
    {
        HttpWebRequest request = null;
        HttpWebResponse response = null;
        // 构造函数
        public MainPage()
        {
            InitializeComponent();
            string uri="http://fpad.ce.cn/hg/news_list.xml";

            request = (HttpWebRequest)WebRequest.Create(uri);
            request.Method = "POST";
            request.BeginGetResponse(new AsyncCallback(GetResponseCallBack), null);
        }

        private void GetResponseCallBack(IAsyncResult ar)
        {
            List<News> newList = new List<Finace.News>();

            response = (HttpWebResponse)request.EndGetResponse(ar);
            using (Stream stream = response.GetResponseStream())
            {
                StreamReader reader = new StreamReader(stream,new Gb2312Encoding());

                using (XmlReader xmlReader = XmlReader.Create(reader))
                {
                    string title = "";
                    string intro = "";

                    while (xmlReader.Read())
                    {
                        try
                        {
                            if (xmlReader.ReadToFollowing("a"))
                            {
                                title = xmlReader.ReadElementContentAsString();
                            }
                            if (xmlReader.ReadToFollowing("summary"))
                            {
                                intro = xmlReader.ReadElementContentAsString();
                            }
                        }
                        catch(Exception ex)
                        {
                            MessageBox.Show(ex.ToString());
                        }

                        if (title != "" || intro != "")
                        {