AsyncTask的链接在活动（回调？） [英] AsyncTask chaining in Activity (callback?)
问题描述
我想链数的AsyncTask 班一个活动里面，那么它会显示另一个活动一旦全部建成（成功）。目前，我链接它们赶走对方的 onPostExecute（）方法，但我不喜欢这个，因为它有些夫妇实施不必要的。
I am trying to chain a few AsyncTask classes inside a single Activity, which will then show another Activity once they are all completed (successfully). Currently I am chaining them off each others' onPostExecute() method but I do not like this because it somewhat couples the implementations unnecessarily.
例如，我有我的 ImportVideoActivity 该用户进入YouTube网址进行下载。要做到这一点，我有两个的AsyncTask 类：
For example, I have my ImportVideoActivity which the users enters a YouTube URL to be downloaded. To do so, I have two AsyncTask classes:
-
YouTubeVideoInfoTask：获取视频元数据信息，以及通过提供视频格式枚举（质量和codeCS） -
YouTubeVideoDownloadTask：鉴于执行从视频信息元数据的URL下载影片
YouTubeVideoInfoTask: Gets the video metadata info as well as enumerating through available video formats (quality and codecs).YouTubeVideoDownloadTask: Performs the video download given a URL from the video info metadata.
我要的 ImportVideoActivity 来首先执行 YouTubeVideoInfoTask 来枚举视频质量，并挑选最好的一个。在此之后，它应该执行 YouTubeVideoDownloadTask ，完成之后启动 CropVideoActivity 通过下载的视频。
I want the ImportVideoActivity to first execute a YouTubeVideoInfoTask to enumerate the video qualities and pick the best one. After that, it should execute a YouTubeVideoDownloadTask and upon completion start the CropVideoActivity with the downloaded video.
我怎样才能优雅链里面的 ImportVideoActivity 这两个的AsyncTask 类？是否有某种监听器/回调，让我来监控这些任务的完成，并开始不使用 AsyncTask.onPostExecute（）方法下一个？
How can I chain these two AsyncTask classes elegantly inside of the ImportVideoActivity? Is there some kind of listener/callback that allows me to monitor when these tasks complete and start the next one without using the AsyncTask.onPostExecute() method?
推荐答案
是的。在活动中使用一个回调监听。只要这就是所谓的，你可以从你的活动开始新的AsyncTask的。
Yes. Use a Callback Listener in your Activity. As soon as this is called, you can start the new AsyncTask from your Activity.
在我的其他答案示例：<一href=\"http://stackoverflow.com/questions/23924483/how-to-return-an-object-from-the-asynctask-to-the-main-class-in-android/23924523#23924523\">How从AsyncTask的Android中返回一个对象主类
Example in my other answer: How to return an object from the asynctask to the main class in android
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