C# Yibu Codec: 发送异步HTTP请求与数据处理

class HttpClient
    {
        //载入数据成功后的回调
        public delegate void LoadDataCompleted(string result);
        private LoadDataCompleted m_comp;
        public LoadDataCompleted OnLoadDataCompleted
        {
            set { m_comp = value; }
        }

        //连接webClient
        public void MyWebClient(string url)
        {
            var webClient = new WebClient();
            webClient.CancelAsync();
            webClient.Headers["pragma"] = "no-cache";
            webClient.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted);
            webClient.OpenReadAsync(new Uri(url));
        }
        void webClient_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            if (e.Error == null && !e.Cancelled)
            {
                //解析流 转化为XML 
                byte[] buff = new byte[e.Result.Length];
                e.Result.Read(buff, 0, buff.Length);
                string str = Encoding.UTF8.GetString(buff, 0, buff.Length);
                e.Result.Close();

                if (null != m_comp)