HttpWebRequest调用webservice

 1  public string GetCostWebservide()
 2         {
 3             string uri = "http://125.77.254.142:8011/WXService.asmx/GetCost"; 
 4             HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create(uri);
 5             string param = String.Empty;
 6             param += String.Format("callback=1&CarNo={0}&monthNum={1}&CarColor={2}", System.Web.HttpUtility.UrlEncode("闽D1F760"), "1", System.Web.HttpUtility.UrlEncode("蓝"));
 7             //param = (param);
 8             byte[] bs = Encoding.ASCII.GetBytes(param);
 9             myHttpWebRequest.Method = "POST";
10             myHttpWebRequest.ContentType = "application/x-www-form-urlencoded";
11             myHttpWebRequest.ContentLength = bs.Length;
12             myHttpWebRequest.GetRequestStream().Write(bs, 0, bs.Length);
13             myHttpWebRequest.Credentials = CredentialCache.DefaultCredentials;
14             HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
15             //如果无法访问外网或者
16             if (myHttpWebResponse.StatusCode != HttpStatusCode.OK)
17             {
18                 myHttpWebResponse.Close();
19                 return uri;
20             }
21             else
22             {
23                 Stream st = myHttpWebResponse.GetResponseStream();
24                 StreamReader sr = new StreamReader(st);
25                 string res = sr.ReadToEnd();
26                 sr.Close();
27                 st.Close();
28                 myHttpWebResponse.Close();
29                 return res;
30             }