HttpWebRequest写入字符串或者字节

第一种方式复杂json格式经常出错：写入已经关闭、或者api转换错误，第二种可以

1、

public static string HttpPost1(string Url, string postDataStr, string contentType = "application/x-www-form-urlencoded")
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
            request.Method = "POST";
            request.ContentType =contentType;
            //request.ContentLength = Encoding.UTF8.GetByteCount(postDataStr);
            Stream myRequestStream = request.GetRequestStream();
            StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.UTF8);
            myStreamWriter.Write(postDataStr);
            myStreamWriter.Close();

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            string retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();

            return retString;
        }

2、

public static string HttpPost2(string Url, string postDataStr, string contentType = "application/x-www-form-urlencoded")
        {
            byte[] bytes = Encoding.UTF8.GetBytes(postDataStr);
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
            request.Method = "POST";
            request.ContentLength = bytes.Length;
            request.ContentType = contentType;
            Stream reqstream = request.GetRequestStream();
            reqstream.Write(bytes, 0, bytes.Length);

            //声明一个HttpWebRequest请求  
            request.Timeout = 90000;
            //设置连接超时时间  
            request.Headers.Set("Pragma", "no-cache");
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream streamReceive = response.GetResponseStream();
            Encoding encoding = Encoding.UTF8;

            StreamReader streamReader = new StreamReader(streamReceive, encoding);
            string strResult = streamReader.ReadToEnd();
            streamReceive.Dispose();
            streamReader.Dispose();

            return strResult;
        }