// post请求   application/json

 

 public string SendPost(string url, string dtStr)         {             HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);             byte[] requestBytes = System.Text.Encoding.UTF8.GetBytes(dtStr);             req.Method = "POST";             req.ContentType = "application/json";             req.ContentLength = requestBytes.Length;             Stream requestStream = req.GetRequestStream();             requestStream.Write(requestBytes, 0, requestBytes.Length);             requestStream.Close();

            HttpWebResponse res = (HttpWebResponse)req.GetResponse();             StreamReader sr = new StreamReader(res.GetResponseStream(), System.Text.Encoding.UTF8);             string result = sr.ReadToEnd();             sr.Close();             res.Close();             return result;         }

//

public string SendPost2(string url, Dictionary<string, object> obj)         {             HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);             string dataStr = JsonConvert.SerializeObject(obj);             byte[] requestBytes = System.Text.Encoding.UTF8.GetBytes(dataStr);             req.Method = "POST";             req.ContentType = "application/json";             req.ContentLength = requestBytes.Length;             Stream requestStream = req.GetRequestStream();             requestStream.Write(requestBytes, 0, requestBytes.Length);             requestStream.Close();

            HttpWebResponse res = (HttpWebResponse)req.GetResponse();             StreamReader sr = new StreamReader(res.GetResponseStream(), System.Text.Encoding.UTF8);             string result = sr.ReadToEnd();             sr.Close();             res.Close();             return result;         }

 

// 2 application/x-www-form-urlencoded

 public string SendPost3(string url, string dtStr)         {             HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);             byte[] requestBytes = System.Text.Encoding.UTF8.GetBytes(dtStr);             req.Method = "POST";             req.ContentType = "application/x-www-form-urlencoded";             req.ContentLength = requestBytes.Length;             Stream requestStream = req.GetRequestStream();             requestStream.Write(requestBytes, 0, requestBytes.Length);             requestStream.Close();

            HttpWebResponse res = (HttpWebResponse)req.GetResponse();             StreamReader sr = new StreamReader(res.GetResponseStream(), System.Text.Encoding.UTF8);             string result = sr.ReadToEnd();             sr.Close();             res.Close();             return result;         }

 

// get请求

 public string SendGet(string url) {             HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);             req.Method = "GET";             req.ContentType = "application/json";

            HttpWebResponse res = (HttpWebResponse)req.GetResponse();             StreamReader sr = new StreamReader(res.GetResponseStream(), System.Text.Encoding.UTF8);             string result = sr.ReadToEnd();             sr.Close();             res.Close();             return result;         }