1：POST方式提交：

<strong><span style="font-size:14px;">private static string HttpPostConnectToServer(string serverUrl, string postData)

        {

            var dataArray = Encoding.UTF8.GetBytes(postData);

            //创建请求

            var request = (HttpWebRequest)HttpWebRequest.Create(serverUrl);

            request.Method = "POST";

            request.ContentLength = dataArray.Length;

            //设置上传服务的数据格式

            request.ContentType = "application/x-www-form-urlencoded";

            //请求的身份验证信息为默认

            request.Credentials = CredentialCache.DefaultCredentials;

            //请求超时时间

            request.Timeout = 10000;

            //创建输入流

            Stream dataStream;

            //using (var dataStream = request.GetRequestStream())

            //{

            //    dataStream.Write(dataArray, 0, dataArray.Length);

            //    dataStream.Close();

            //}

            try

            {

                dataStream = request.GetRequestStream();

            }

            catch (Exception)

            {

                return null;//连接服务器失败

            }

            //发送请求

            dataStream.Write(dataArray, 0, dataArray.Length);

            dataStream.Close();

            //读取返回消息

            string res;

            try

            {

                var response = (HttpWebResponse)request.GetResponse();

                var reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);

                res = reader.ReadToEnd();

                reader.Close();

            }

            catch (Exception ex)

            {

                var result = new ServerResult();

                return "{\"error\":\"connectToServer\",\"error_description\":\"" + ex.Message + "\"}";//连接服务器失败

            }

            return res;

        }</span></strong>

2：GET方式提交：

<strong><span style="font-size:14px;">private static string HttpGetConnectToServer(string serverUrl, string postData)

        {

            //创建请求

            var request = (HttpWebRequest)HttpWebRequest.Create(serverUrl + "?" + postData);

            request.Method = "GET";

            //设置上传服务的数据格式

            request.ContentType = "application/x-www-form-urlencoded";

            //请求的身份验证信息为默认

            request.Credentials = CredentialCache.DefaultCredentials;

            //请求超时时间

            request.Timeout = 10000;

            //读取返回消息

            string res;

            try

            {

                var response = (HttpWebResponse)request.GetResponse();

                var reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);

                res = reader.ReadToEnd();

                reader.Close();

            }

            catch (Exception ex)

            {

                var result = new ServerResult();

                return "{\"error\":\"connectToServer\",\"error_description\":\"" + ex.Message + "\"}";

            }

            return res;

        }</span></strong>

3：调用方法：

<strong><span style="font-size:14px;">//服务地址

    var serverUrl ="https://openapi.baidu.com/rest/2.0/devapi/v1/lightapp/query/isonline";

 //上传的数据

    var postData = string.Format("access_token={0}&offline_app_id={1}", token, appId);</span></strong>