HttpWebResponse获取网页乱码

string html = "";
string url = "http://www.stats.gov.cn/tjsj/tjbz/tjyqhdmhcxhfdm/2018/11/1101.html";
HttpWebRequest myReq = (HttpWebRequest)HttpWebRequest.Create(url);
myReq.Timeout = 5000;//5s
using (HttpWebResponse httpWResp = (HttpWebResponse)myReq.GetResponse())
{
Stream myStream = httpWResp.GetResponseStream();
//如果包含GZIP,需要解压

if (!string.IsNullOrEmpty(httpWResp.ContentEncoding)
&& httpWResp.ContentEncoding.ToUpper().IndexOf("GZIP") > -1)
{
System.IO.StreamReader sr =
new System.IO.StreamReader(new GZipStream(myStream, CompressionMode.Decompress), Encoding.Default);
html = sr.ReadToEnd();
sr.Close();
}
else
{
StreamReader sr = new StreamReader(myStream, Encoding.Default);
html = sr.ReadToEnd();
sr.Close();
}
myStream.Close();
httpWResp.Close();