我的HttpWebRequest " post;自从我升级到Microsoft.NETCore.Univers

我注意到Microsoft.NETCore.UniversalWindowsPlatform的v5.2和5.1之间有一些东西

我有一个应用程序在v5.1和做一个"POST"操作与HttpWebRequest，参数在正文编码UTF8。(模拟登入网站)如果升级到v5.2，我的POST停止工作!我恢复到v5.1，它又工作了!你有什么主意吗?

mycode

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(urlrest.AbsoluteUri); request.CookieContainer = new CookieContainer();
ASCIIEncoding encoding = new ASCIIEncoding();
//Encoding.UTF8.GetBytes(postString);
byte[] postData = Encoding.UTF8.GetBytes(allparaminbody); //allparamin_body contain : user=myuser&password=mypassword
request.ContentType = "POST";
request.Headers["User-Agent"] = "Apache-HttpClient/4.1.1 (java 1.5)";
Stream newStream = await request.GetRequestStreamAsync();
newStream.Write(postData, 0, postData.Length);
newStream.Dispose();
response = (HttpWebResponse)await request.GetResponseAsync();

谢谢