HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.baidu.com/");

HttpWebResponse response = (HttpWebResponse)request.GetResponse();

Stream receiveStream = response.GetResponseStream();

StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);

string responseData = readStream.ReadToEnd();

response.Close();

readStream.Close();
Response.Write(responseData);

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.webxml.com.cn/WebServices/WeatherWebService.asmx/getSupportCity");

string data = "byProvinceName=河北";

byte[] bs = Encoding.UTF8.GetBytes(data);

string responseData;

request.Method = "POST";

request.ContentLength = bs.Length;

request.ContentType = "application/x-www-form-urlencoded";

using (Stream reqStream = request.GetRequestStream())

{

    reqStream.Write(bs, , bs.Length);

    reqStream.Close();

}

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())

{

    using (StreamReader readStream = new StreamReader(response.GetResponseStream(), Encoding.UTF8))

    {

        responseData = readStream.ReadToEnd().ToString();

        readStream.Close();

    }

    response.Close();

}

Response.Write(responseData);