WP7 后台音频资源不再可用 [英] WP7 background audio resources are no longer available

问题描述

我正在将 BackgroundAudioPlayer 用于我的 Windows Phone 7 音乐&视频应用.播放一些音乐后，我使用 MediaPlayerLauncher 播放视频，然后按 Back 返回到我的应用程序.每当我使用 BackgroundAudioPlayer.Instance 时就在那里.我收到错误背景音频资源不再可用".

I'm using BackgroundAudioPlayer for my Windows Phone 7 music & video application. After I play some music, I play video using MediaPlayerLauncher, then press Back to return to my app. There whenever I use BackgroundAudioPlayer.Instance. I receive error "The background audio resources are no longer available".

MSDN 上的某人 建议使用 try/catch，但这不是一个好主意，并且会减慢应用程序的速度.

Someone on MSDN suggests using try/catch, but this is not a good idea, and can slow down the app.

其他建议在启动 MediaPlayer 之前调用 BackgroundAudioPlayer.Instance.Close().但是，当我播放音乐时，代理再次加载.dll，这需要很长时间.

Other suggests call BackgroundAudioPlayer.Instance.Close() before launch MediaPlayer. However, when I play music, the agent load .dll again, which takes very much time.

如何解决这个问题?

推荐答案

如果您在播放完音频后播放视频，操作系统肯定会终止"您的后台音频播放器.从您的问题来看，这似乎是 100% 可重现的，这将证实这一点.您唯一的选择是在您调用 BackgroundAudioPlayer.Instance.Close() 后再次重新启动后台音频播放器，然后播放您的视频.正如您所说，当您启动 BAP 时，需要重新加载您的播放器 DLL.

If you play a video after your audio the OS will definitely "terminate" your Background Audio Player. From your question it seems this is reproducible 100% of the time which would confirm this. Your only option is to restart the background audio player again after you have called BackgroundAudioPlayer.Instance.Close(), and then played your video. Which as you said will require reloading your player DLL when you start the BAP.

根据评论更新跟进

如果您没有实现流式音频代理，而只是实现了 AudioPlayer 代理，那么无论如何您都无法杀死进程.操作系统在需要让您处理操作(例如:用户操作、跟踪结束、关闭)时启动进程.

If you aren't implementing a streaming audio agent but only an AudioPlayer agent there isn't a process for you to kill anyway. The OS spins up a process as and when it needs to get you to process an action (e.g.: user action, track ended, shutdown).

BackgroundAudioPlayer.Instance.Close() 只是确保操作系统在 OP 等场景中干净地释放这些资源.

BackgroundAudioPlayer.Instance.Close() just makes sure that the OS releases those resources cleanly in a scenario such as the OP has.

要重新启动背景音频，只需再次调用BackgroundAudioPlayer.Instance.Play().

To restart background audio, just call BackgroundAudioPlayer.Instance.Play() again.

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