c#发送简单的post、get请求

• POST发送请求及接受响应流程 

1. 根据目标地址址创建HttpWebRequest对象
2. 设置响应的请求参数------Method、ContentType 等
3. 使用HttpWebRequest对象获取请求流并且写入消息体   
4. 使用HttpWebRequest对象获取响应流并读取流中数据(在获取过程中就是发送请求并接受响应)

• GET发送请求及接受响应流程

1. 把目标地址和查询字符串拼接在一起(如果有查询字符串)使用拼接的字符串创建HttpWebRequest对象
2. 设置响应的请求参数------Method、ContentType 等
3. 使用HttpWebRequest对象获取响应流并读取流中数据(在获取过程中就是发送请求并接受响应)

   以下为代码：

        两个请求方法 和读取方法

        /// <summary>
        /// 发送http post请求
        /// </summary>
        /// <param name="url">地址</param>
        /// <param name="parameters">查询参数集合</param>
        /// <returns></returns>
        public HttpWebResponse CreatePostHttpResponse(string url, IDictionary<string, string> parameters)
        {
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;//创建请求对象
            request.Method = "POST";//请求方式
            request.ContentType = "application/x-www-form-urlencoded";//链接类型
            //构造查询字符串
            if (!(parameters == null || parameters.Count == 0))
            {
                StringBuilder buffer = new StringBuilder();
                bool first = true;
                foreach (string key in parameters.Keys)
                {

                    if (!first)
                    {
                        buffer.AppendFormat("&{0}={1}", key, parameters[key]);
                    }
                    else
                    {
                        buffer.AppendFormat("{0}={1}", key, parameters[key]);
                        first = false;
                    }
                }
                byte[] data = Encoding.UTF8.GetBytes(buffer.ToString());
                //写入请求流
                using (Stream stream = request.GetRequestStream())
                {
                    stream.Write(data, 0, data.Length);
                }
            }
            return request.GetResponse() as HttpWebResponse;
        }
        /// <summary>
        /// 发送http Get请求
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        public static HttpWebResponse CreateGetHttpResponse(string url)
        {
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            request.ContentType = "application/x-www-form-urlencoded";//链接类型
            return request.GetResponse() as HttpWebResponse;
        }
        /// <summary>
        /// 从HttpWebResponse对象中提取响应的数据转换为字符串
        /// </summary>
        /// <param name="webresponse"></param>
        /// <returns></returns>
        public string GetResponseString(HttpWebResponse webresponse)
        {
            using (Stream s = webresponse.GetResponseStream())
            {
                StreamReader reader = new StreamReader(s, Encoding.UTF8);
                return reader.ReadToEnd();
            }
        }

　　调用

//post请求并调用

Dictionary<string, string> dic = new Dictionary<string, string>();
dic.Add("id", "4");
textBox1.Text = GetResponseString(CreatePostHttpResponse("https://www.baidu.com/", dic));
//get请求并调用

textBox3.Text = GetResponseString(CreateGetHttpResponse("https://i.cnblogs.com/EditPosts.aspx?opt=1"));