Android API Guide for Media Apps（九）——媒體會話的回調（Media Session Callbacks）

Media Session Callbacks

一旦是視訊app在同一個activity中運作媒體會話和媒體控制器，媒體會話回調的實作與音頻應用server/client 架構實作的回調不同。由于沒有服務的調用，是以notification都是由NotificationManager來控制的。下面的清單展示兩種回調函數中不同的控制方式。

_	onPlay()	onPause()	onStop()
Audio Focus	requestFocus() passing in your OnAudioFocusChangeListener. Always call requestFocus() first, proceed only if focus is granted.	abandonAudioFocus()
Media Session	setActive(true) - Update metadata and state	-Update metadata and state	setActive(false) - Update metadata and state
Player Implementation	Start the player	Pause the player	Stop the player
Becoming Noisy	Register your BroadcastReceiver	Unregister your BroadcastReceiver
Notifications	Show notification	Update notification	Cancel notification