When my app is launched (no sound emitted, Ambiant category set for AudioSession), using the up and down volume button on the iPhone does not do anything : - on screen, nothing is displayed (I mean, the iOS black and white "slider" overlay does not appear to show me that volume is changing). - in app, after playing with hard buttons, no impact on the sound volume when some sound is played (I use an AVAudioPlayer) - this is the same if I quit the app, adjust the sound volume (onscreen "slider"overlay shows up to show me that the sound level have decreased for example), kill the app and relaunch it : same sound level that before
使用这些硬按钮可以在跳板上和其他应用程序中工作（显示“滑块”覆盖，音量也在变化）。
我的应用程序有什么问题？
据我所见，许多应用程序，例如愤怒的小鸟，都会发出声音，在玩游戏时没有硬滑块来改变音量，只需使用硬按钮就可以调整声音。