.net Post Json数据

public string PostJsonTo(string postUrl, string referUrl, string data)
{
string result = "";
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(postUrl);
request.Accept = "text/plain, */*; q=0.01";
request.Referer = referUrl;
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)";
request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
request.Method = "POST";
request.KeepAlive = true;
request.AllowAutoRedirect = true;
request.Headers.Add("Accept-Encoding", "gzip, deflate");
Stream postStream = request.GetRequestStream();
byte[] postData = Encoding.UTF8.GetBytes(data);
postStream.Write(postData, 0, postData.Length);
postStream.Dispose();
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
if (response.ContentEncoding == "gzip")
{
MemoryStream ms = new MemoryStream();
GZipStream zip = new GZipStream(response.GetResponseStream(), CompressionMode.Decompress);
byte[] buffer = new byte[1024];
int l = zip.Read(buffer, 0, buffer.Length);
while (l > 0)
{
ms.Write(buffer, 0, l);
l = zip.Read(buffer, 0, buffer.Length);
}
ms.Dispose();
zip.Dispose();
result = Encoding.UTF8.GetString(ms.ToArray());
}
else
{
Stream respStream = response.GetResponseStream();
StreamReader RespStreamReader = new StreamReader(respStream, Encoding.UTF8);
result = RespStreamReader.ReadToEnd();
}
return result;
}
catch (Exception)
{
throw;
}
}