get方式：
string url = "http://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true";
WebRequest request = WebRequest.Create(url);
WebResponse response = request.GetResponse();
Stream s = response.GetResponseStream();
StreamReader sr = new StreamReader(s, Encoding.GetEncoding("gb2312"));
MessageBox.Show(sr.ReadToEnd());
sr.Dispose();
sr.Close();
s.Dispose();
s.Close();
post方式：
string url = http://maps.googleapis.com/maps/api/geocode/json;
string postData = "address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=true";
WebRequest request = WebRequest.Create(url);
request.Method = "Post";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = postData.Length;
StreamWriter sw = new StreamWriter(request.GetRequestStream());
sw.Write(postData);
sw.Flush();
WebResponse response = request.GetResponse();
Stream s = response.GetResponseStream();
StreamReader sr = new StreamReader(s, Encoding.GetEncoding("gb2312"));
MessageBox.Show(sr.ReadToEnd());
sw.Dispose();
sw.Close();
sr.Dispose();
sr.Close();
s.Dispose();
s.Close();