如何在Windows Phone 7中添加背景音频？

// 播放音频
BackgroundAudio.Play();

// 暂停音频
BackgroundAudio.Pause();

// 停止音频
BackgroundAudio.Stop();

// 更改音量
BackgroundAudio.Volume = 0.8;

// 设置音频源
BackgroundAudio.Source = new Uri("Assets/Audio/background_audio.mp3", UriKind.Relative);

private void PhoneApplicationService_Activated(object sender, ActivatedEventArgs e)
{
    BackgroundAudio.Play();
}

private void PhoneApplicationService_Deactivated(object sender, DeactivatedEventArgs e)
{
    BackgroundAudio.Pause();
}