C# 发送Post请求（带参数）

此处内容传输都是用UTF-8编码

1.不带参数发送Post请求

/// <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 static string Post(string url)

        {

            string result = "";

            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);

            req.Method = "POST";

            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();

            Stream stream = resp.GetResponseStream();

            //获取内容

            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))

            {

                result = reader.ReadToEnd();

            }

            return result;

        }

2.带参数Post请求,指定键值对

    /// <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 static string Post(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;

        }

3.带参数的Post请求，指定发送字符串内容

/// <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>

/// <param name="content">Post提交数据内容(utf-8编码的)</param>

/// <returns></returns>

public static string Post(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;

}

转载方法：

 HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("http://fanyi.baidu.com/transcontent");

            Encoding encoding = Encoding.UTF8;

            string param = "ie=utf-8&source=txt&query=hello&t=1327829764203&token=8a7dcbacb3ed72cad9f3fb079809a127&from=auto&to=auto";

            //encoding.GetBytes(postData);

            byte[] bs = Encoding.ASCII.GetBytes(param);

            string responseData = String.Empty;

            req.Method = "POST";

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

            req.ContentLength = bs.Length;

            using (Stream reqStream = req.GetRequestStream())

            {

                reqStream.Write(bs, 0, bs.Length);

                reqStream.Close();

            }

            using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())

            {

                using (StreamReader reader = new StreamReader(response.GetResponseStream(),encoding))

                {

                    responseData = reader.ReadToEnd().ToString();

                }

                context.Response.Write(responseData);

            }