使用异步枚举器

我一直在使用AsyncEnumerator类来帮助清理异步代码。问题是收益率返回后的代码永远不会触发。UI调用一个对象,该对象在单击按钮时调用HttpWorker对象。无论点击多少按钮,代码都不会超过收益率。

    public void ReadFromUrl(string Url)
    {
        AsyncEnumerator asyncEnum = new AsyncEnumerator();
        asyncEnum.BeginExecute(GetData(asyncEnum,Url), asyncEnum.EndExecute);
    }

    private IEnumerator<Int32> GetData(AsyncEnumerator AsyncEnum, String Url)
    {
        url = Url;
        request = (HttpWebRequest)WebRequest.Create(url);

        request.CookieContainer = new CookieContainer();
        request.AllowAutoRedirect = true;
        request.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5.0.6";

        request.BeginGetResponse(AsyncEnum.End(), null);
        AsyncEnum.SyncContext = null;
        yield return 1;

        response = (HttpWebResponse)request.EndGetResponse(AsyncEnum.DequeueAsyncResult());


        if (response.StatusCode == HttpStatusCode.OK)
        {
            // Create the stream, encoder and reader.
            Stream responseStream = response.GetResponseStream();
            Encoding streamEncoder = Encoding.UTF8;
            StreamReader responseReader = new StreamReader(responseStream, streamEncoder);
            responseAsString = responseReader.ReadToEnd();
        }
        else
        {
            throw new Exception(String.Format("Response Not Valid {0}", response.StatusCode));
        }

    }