WebClient wc = new WebClient();
Byte[] pageData = wc.DownloadData("http://xxxx.com");
hd_num.Value = Encoding.Default.GetString(pageData);
前臺代碼：asp:HiddenField ID="hd_num" runat="server" />
再通過js獲取hd_num的值。

HttpWebRequest request = HttpWebRequest.Create("http://xxx/aaa.ashx") as HttpWebRequest;
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
Stream resStream = response.GetResponseStream();
StreamReader sr = new StreamReader(resStream, System.Text.Encoding.Default); //編碼可以改成別的
ContentHtml.Text = sr.ReadToEnd();