Android笔记之多个Activity的生命周期交互
单个Activity:
应用开启时调用：onCreate(),onStart(),onResume();
按下返回键：onPause(),onStop(),onDestory();
多个Activity之间交互时：
跳转至第二个Activity时：
| FirstActivity | SecondActivity |
| onPause() | |
|
onCreate() |
|
| onStart() | |
| onResume() | |
| onStop() |
按下锁屏键
| SecondActivity |
| onPause() |
| onStop() |
解锁
| SecondActivity |
| onRestart() |
| onStart() |
| onResume() |
按下返回键，或者SecondActivity调用finish()
| FirstActivity | SecondActivity |
| onPause() | |
| onRestart() | |
| onStart() | |
| onResume() | |
| onStop() | |
| onDestory() |
生命周期应用实例
在Activity中播放音乐
oncreate()：
1 private MediaPlayer mediaplayer; 2 @Override 3 protected void onCreate(Bundle savedInstanceState) { 4 super.onCreate(savedInstanceState); 5 setContentView(R.layout.activity_main); 6 Log.i("imformation", "MainActivity onCreate!"); 7 mediaplayer=MediaPlayer.create(this, R.raw.quite); 8 mediaplayer.start(); 9 10 }
在Activity onPause时，音乐也需要暂停
此时，需要一个记录播放到的位置的变量：private int place;
onPause:
1 @Override 2 protected void onPause() { 3 // TODO Auto-generated method stub 4 super.onPause(); 5 if(mediaplayer.isPlaying()) 6 { 7 mediaplayer.pause(); 8 place=mediaplayer.getCurrentPosition(); 9 10 } 11 Log.i("imformation", "MainActivity onPause!"); 12 }
同样，当Activity Resume时，音乐也要接着播放
onResume:
1 @Override 2 protected void onResume() { 3 // TODO Auto-generated method stub 4 super.onResume(); 5 if(place!=0) 6 { 7 mediaplayer.seekTo(place); 8 mediaplayer.start(); 9 } 10 Log.i("imformation", "MainActivity onResume!"); 11 }
当Activity 销毁时，音乐播放器也要销毁
1 @Override 2 protected void onDestroy() { 3 // TODO Auto-generated method stub 4 super.onDestroy(); 5 if(mediaplayer!=null){ 6 mediaplayer.release(); 7 mediaplayer=null; 8 } 9 Log.i("imformation", "MainActivity onDestory!"); 10 }
注：本文是学习慕课网Android-重识Activity（http://www.imooc.com/learn/384）时的笔记，如有侵权行为，立即删除
