我正在创建一个与 HTTP 侦听器服务对话的应用程序。
我已经从这个Posting Posting with HttpWebRequest on Windows Phone 7中获取了代码
这段代码似乎工作得几乎完美，只是在第一次调用时就不起作用。
该调用正在访问服务并且没有引发错误。只是返回值是空的。
在第二次通话中，我毫无问题地获得了返回值。如果我转到另一个页面并再次返回，我也会第一次获得返回值。这只发生在应用程序首次启动时的第一次调用中。
任何想法将不胜感激。代码如下。
服务
DiagnosticLog.Write(99, DateTime.Now, "Phone Listener Called");
IAsyncResult phoneResult = PhoneListener.BeginGetContext(new AsyncCallback(Phone), PhoneListener);
HttpListenerContext context = null;
HttpListenerResponse response = null;
HttpListener _listener = (HttpListener)result.AsyncState;
context = _listener.EndGetContext(result);
HttpListenerRequest request = context.Request;
response = context.Response;
//response.ContentType = "text/plain";
string postData = string.Empty;
using (StreamReader sr = new StreamReader(request.InputStream))
{
DiagnosticLog.Write(99, DateTime.Now, "Reading Stream");
postData = sr.ReadToEnd();
}
byte[] buffer;
System.IO.Stream output = response.OutputStream;
if (postData == "islogin")
{
buffer = System.Text.Encoding.UTF8.GetBytes("logincorrect");
// Get a response stream and write the response to it.
response.ContentLength64 = buffer.Length;
output = response.OutputStream;
output.Write(buffer, 0, buffer.Length);
DiagnosticLog.Write(99, DateTime.Now, "Good Return sent");
output.Close();
}
else
{
buffer = System.Text.Encoding.UTF8.GetBytes("loginincorrect");
// Get a response stream and write the response to it.
response.ContentLength64 = buffer.Length;
output = response.OutputStream;
output.Write(buffer, 0, buffer.Length);
DiagnosticLog.Write(99, DateTime.Now, "Bad Return sent");
output.Close();
}
代码（手机应用程序）
WebRequest request = WebRequest.Create("http://127.0.0.1:8080/phone");
request.Method = "POST";
request.BeginGetRequestStream(ar =>
{
var requestStream = request.EndGetRequestStream(ar);
using (StreamWriter sw = new StreamWriter(requestStream))
{
sw.Write("islogin");
}
request.BeginGetResponse(a =>
{
try
{
WebResponse response = request.EndGetResponse(a);
Stream responseStream = response.GetResponseStream();
using(var sr = new StreamReader(responseStream))
{
Storage.ReturnValue = sr.ReadToEnd().ToString();
}
}
catch(WebException ex)
{
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
MessageBox.Show(ex.ToString());
});
}
}, null);
}, null);
txtLoginUsername.Text = Storage.ReturnValue;