POST GET 请求示例

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, 0, 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);