HttpWebRequest , HttpWebResponse 调用示例

1，

        public string sendPost1(string url, string content)
        {
            string result = "";
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";

            #region 添加Post 参数
            byte[] data = Encoding.UTF8.GetBytes(content);
            req.ContentLength = data.Length;
            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(data, 0, data.Length);
                reqStream.Close();
            }
            #endregion

            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
            Stream stream = resp.GetResponseStream();
            //获取响应内容
            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {
                result = reader.ReadToEnd();
            }
            return result;
        }

2，

        protected string sendPost2(string url, string postData)
        {
            HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(url);
            webrequest.Method = "post";
            webrequest.ContentType = "application/json;charset=utf-8";
            byte[] postdatabyte = Encoding.UTF8.GetBytes(postData);
            webrequest.ContentLength = postdatabyte.Length;
            Stream stream;
            stream = webrequest.GetRequestStream();
            stream.Write(postdatabyte, 0, postdatabyte.Length);
            stream.Close();
            using (var httpWebResponse = webrequest.GetResponse())
            using (StreamReader responseStream = new StreamReader(httpWebResponse.GetResponseStream()))
            {
                String ret = responseStream.ReadToEnd();
                string result = ret.ToString();
                return result;
            }
        }

3，

        /// <summary>
        /// 指定Post地址使用Get 方式获取全部字符串
        /// </summary>
        /// <param name="url">请求后台地址</param>
        /// <returns></returns>
        public  string sendPost3(string url, Dictionary<string, string> dic)
        {
            string result = "";
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            #region 添加Post 参数
            StringBuilder builder = new StringBuilder();
            int i = 0;
            foreach (var item in dic)
            {
                if (i > 0)
                    builder.Append("&");
                builder.AppendFormat("{0}={1}", item.Key, item.Value);
                i++;
            }
            byte[] data = Encoding.UTF8.GetBytes(builder.ToString());
            req.ContentLength = data.Length;
            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(data, 0, data.Length);
                reqStream.Close();
            }
            #endregion
            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
            Stream stream = resp.GetResponseStream();
            //获取响应内容
            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {
                result = reader.ReadToEnd();
            }
            return result;
        }