c# – 异步HttpListener每次收到两次请求
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了c# – 异步HttpListener每次收到两次请求，小编现在分享给大家，供广大互联网技能从业者学习和参考。文章包含4850字，纯文字阅读大概需要7分钟。
内容图文
我在c#中实现了一个异步http监听器.
我按照here by Microsoft提供的教程进行操作
并发现另一个教程,我愚蠢地没有书签,现在再也找不到了.这意味着我有一些代码,我自己不会这样写,但所提供的解释是有道理的,所以我遵循了这一点.
现在我面临两个问题：
首先,我必须在使用Listener.Stop()的每个请求之后重新启动侦听器,然后再次调用StartListening方法,其次,当我这样做时,我会收到两次请求.
请求发送net get两次,但我收到两次.
然而,当我暂停我正在收听的线程大约2秒时,它不会被接收两次.
我很抱歉,如果我的解释很模糊,但我对我的问题的理解也是如此,我不知道是什么导致了它.
由于回调方法是大多数事情发生的地方,我将发布它,请告诉我你是否需要更多的代码.
任何帮助都将很高兴,因为我真的被困在这一个.
public void ListenAsynchronously()
{
if (listener.Prefixes.Count == 0) foreach (string s in prefixes) listener.Prefixes.Add(s);
try
{
listener.Start();
}
catch (Exception e)
{
Logging.logException(e);
}
System.Threading.ThreadPool.QueueUserWorkItem(new System.Threading.WaitCallback(Listen));
}
private void Listen(object state)
{
while (listener.IsListening)
{
listener.BeginGetContext(new AsyncCallback(ListenerCallback), listener);
listenForNextRequest.WaitOne();
}
}
private void ListenerCallback(IAsyncResult ar)
{
HttpListener httplistener = ar.AsyncState as System.Net.HttpListener;
System.Net.HttpListenerContext context = null;
int requestNumber = System.Threading.Interlocked.Increment(ref requestCounter);
if (httplistener == null) return;
try
{
context = httplistener.EndGetContext(ar);
}
catch(Exception ex)
{
return;
}
finally
{
listenForNextRequest.Set();
}
if (context == null) return;
System.Net.HttpListenerRequest request = context.Request;
if (request.HasEntityBody)
{
using (System.IO.StreamReader sr = new System.IO.StreamReader(request.InputStream, request.ContentEncoding))
{
string requestData = sr.ReadToEnd();
//Stuff I do with the request happens here
}
}
try
{
using (System.Net.HttpListenerResponse response = context.Response)
{
//response stuff happens here
}
byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
response.ContentLength64 = buffer.LongLength;
response.OutputStream.Write(buffer, 0, buffer.Length);
response.Close();
StopListening();
//If I dont set the thread to sleep here, I receive the double requests
System.Threading.Thread.Sleep(2500);
ListenAsynchronously();
}
}
catch (Exception e)
{
}
}
解决方法:
我不确定你为什么要在ListenerCallback()方法中调用StopListening()和ListenAsynchronously(). Listen()方法正在一个线程中运行,并将继续获取每个下一个传入请求.如果我写这篇文章,我就不会使用HttpListener的实例变量.在ListenAsynchronously方法中创建一个新方法并将其传递给状态对象,例如,
public class HttpListenerCallbackState
{
private readonly HttpListener _listener;
private readonly AutoResetEvent _listenForNextRequest;
public HttpListenerCallbackState(HttpListener listener)
{
if (listener == null) throw new ArgumentNullException("listener");
_listener = listener;
_listenForNextRequest = new AutoResetEvent(false);
}
public HttpListener Listener { get { return _listener; } }
public AutoResetEvent ListenForNextRequest { get { return _listenForNextRequest; } }
}
public class HttpRequestHandler
{
private int requestCounter = 0;
private ManualResetEvent stopEvent = new ManualResetEvent(false);
public void ListenAsynchronously(IEnumerable<string> prefixes)
{
HttpListener listener = new HttpListener();
foreach (string s in prefixes)
{
listener.Prefixes.Add(s);
}
listener.Start();
HttpListenerCallbackState state = new HttpListenerCallbackState(listener);
ThreadPool.QueueUserWorkItem(Listen, state);
}
public void StopListening()
{
stopEvent.Set();
}
private void Listen(object state)
{
HttpListenerCallbackState callbackState = (HttpListenerCallbackState)state;
while (callbackState.Listener.IsListening)
{
callbackState.Listener.BeginGetContext(new AsyncCallback(ListenerCallback), callbackState);
int n = WaitHandle.WaitAny(new WaitHandle[] { callbackState.ListenForNextRequest, stopEvent});
if (n == 1)
{
// stopEvent was signalled
callbackState.Listener.Stop();
break;
}
}
}
private void ListenerCallback(IAsyncResult ar)
{
HttpListenerCallbackState callbackState = (HttpListenerCallbackState)ar.AsyncState;
HttpListenerContext context = null;
int requestNumber = Interlocked.Increment(ref requestCounter);
try
{
context = callbackState.Listener.EndGetContext(ar);
}
catch (Exception ex)
{
return;
}
finally
{
callbackState.ListenForNextRequest.Set();
}
if (context == null) return;
HttpListenerRequest request = context.Request;
if (request.HasEntityBody)
{
using (System.IO.StreamReader sr = new System.IO.StreamReader(request.InputStream, request.ContentEncoding))
{
string requestData = sr.ReadToEnd();
//Stuff I do with the request happens here
}
}
try
{
using (HttpListenerResponse response = context.Response)
{
//response stuff happens here
string responseString = "Ok";
byte[] buffer = Encoding.UTF8.GetBytes(responseString);
response.ContentLength64 = buffer.LongLength;
response.OutputStream.Write(buffer, 0, buffer.Length);
response.Close();
}
}
catch (Exception e)
{
}
}
}
内容总结
以上是互联网集市为您收集整理的c# – 异步HttpListener每次收到两次请求全部内容，希望文章能够帮你解决c# – 异步HttpListener每次收到两次请求所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错，欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 gblab@vip.qq.com 举报，一经查实，本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。