//第1步： 送出要求
string url="https://www.baidu.com/";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
//第2步： 取得回應
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
StreamReader sr = new StreamReader(response.GetResponseStream());
//第3步：得到一个json字符串
string tmpArray = sr.ReadToEnd().ToString();