有没有办法在Windows Phone 8中等待IAsyncResult？

Question

如何在Windows Phone 8中使用等待 HttpWebRequest？

有没有办法让IAsyncResult的东西与await一起工作？

private async Task<int> GetCurrentTemperature()
{
  GeoCoordinate location = GetLocation();

  string url = "http://free.worldweatheronline.com/feed/weather.ashx?q=";
  url += location.Latitude.ToString();
  url += ",";
  url += location.Longitude.ToString();
  url += "&format=json&num_of_days=1&key=MYKEY";

  HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
  webRequest.Method = "POST";
  webRequest.BeginGetResponse(new AsyncCallback(OnGotWebRequest), webRequest);
}

private void OnGotWebRequest(IAsyncResult asyncResult)
{
  HttpWebRequest webRequest = (HttpWebRequest)asyncResult.AsyncState;
  var httpResponse = (HttpWebResponse)webRequest.EndGetResponse(asyncResult);
  using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
  {
    string responseText = streamReader.ReadToEnd();
  }
}

谢谢!

Answer 1

用于从/ 方法TaskFactory.FromAsync创建.然后你可以完全摆脱你的,并为响应做同样的事情.Task<Stream>BeginGetRequestStreamEndGetRequestStreamOnGotWebRequest

需要注意的是目前你调用EndGetResponse一个当BeginGetRequestStream调用完成,这是不合适的开始-你要调用EndFoo相匹配的方法BeginFoo,你原来叫.你的意思是打电话BeginGetResponse吗？