移动短信下发乱码问题

[skcry]

做的个短信下发的东西，调用rt2接口，接口要求的编码是GB2312，下面发下去是乱码，求各位打打解决下，多谢

WebRequest wr = WebRequest.Create(rt2);
wr.Method = "GET";
wr.Timeout = 10000000;
WebResponse rp = wr.GetResponse();

byte[] by = new byte[rp.ContentLength];
rp.GetResponseStream().Read(by, 0, (int)rp.ContentLength);
Console.Write(Encoding.GetEncoding("GB2312").GetString(by));

Console.Read();


请问，我这个编码对吗，下发时候是乱码 ，求解决