Post utf-8 请求

/// <summary>
/// POST请求与获取结果
/// </summary>
public static string HttpPost(string Url, string postDataStr)
{
         //把数组转换成流中所需字节数组类型
            Encoding code = Encoding.GetEncoding("utf-8");
            byte[] bytesRequestData = code.GetBytes(postDataStr);

            //设置HttpWebRequest基本信息
            HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(Url);
            myReq.Method = "post";
            myReq.ContentType = "application/x-www-form-urlencoded";

            //填充POST数据
            myReq.ContentLength = bytesRequestData.Length;
            Stream requestStream = myReq.GetRequestStream();
            requestStream.Write(bytesRequestData, , bytesRequestData.Length);
            requestStream.Close();

            //发送POST数据请求服务器
            HttpWebResponse HttpWResp = (HttpWebResponse)myReq.GetResponse();

            //接收对应的流
            StreamReader reader = new StreamReader(HttpWResp.GetResponseStream());
            string retString = reader.ReadToEnd();

    return retString;
}

--调用

            var result = HttpPost(sendUrl, "id=1&text=" + "这是音频内容");