问HttpListener问题:每个HttpListener请求都会导致HttpListener返回的两个上下文

EN

public void RunService()
{
    var prefix = "http://*:4333/";
    HttpListener listener = new HttpListener();
    listener.Prefixes.Add(prefix);
    try
    {
        listener.Start();
        _logger.Debug(String.Format("Listening on http.sys prefix: {0}", prefix));
    }
    catch (HttpListenerException hlex)
    {
        _logger.Error(String.Format("HttpListener failed to start listening. Error Code: {0}", hlex.ErrorCode));
        return;
    }
    while (listener.IsListening)
    {
        var context = listener.GetContext(); // This line returns a second time through the while loop for each request
        ProcessRequest(context);
    }
    listener.Close();
}

private void ProcessRequest(HttpListenerContext context) 
{
    // Get the data from the HTTP stream
    var body = new StreamReader(context.Request.InputStream).ReadToEnd();
    _logger.Debug(body);

    byte[] b = Encoding.UTF8.GetBytes("OK");
    context.Response.StatusCode = 200;
    context.Response.KeepAlive = false;
    context.Response.ContentLength64 = b.Length;

    var output = context.Response.OutputStream;
    output.Write(b, 0, b.Length);
    output.Close();
    context.Response.Close();
}