Activity的生命周期（五）——Activity生命周期的应用场景

public class UseActivityLife extends Activity implements OnClickListener{

private String TAG = "UseActivityLife";

private MediaPlayer music;
private int positon;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_many_a);
Button btn_switchToB = (Button) findViewById(R.id.btn_switchToB);
btn_switchToB.setOnClickListener(this);
Log.e(TAG, "onCreate");
music = MediaPlayer.create(this, R.raw.beyond);
music.start();
}

@Override
protected void onStart() {
super.onStart();
Log.e(TAG, "onStart");
}

@Override
protected void onRestart() {
super.onRestart();
Log.e(TAG, "onRestart");
}

@Override
protected void onResume() {
super.onResume();
Log.e(TAG, "onResume");
if(positon != 0){
music.seekTo(positon);
music.start();
}
}

@Override
protected void onPause() {
super.onPause();
Log.e(TAG, "onPause");
if(music.isPlaying()){
music.pause();
positon = music.getCurrentPosition();
}
}

@Override
protected void onStop() {
super.onStop();
Log.e(TAG, "onStop");
}

@Override
protected void onDestroy() {
super.onDestroy();
Log.e(TAG, "onDestroy");
if(music != null){
music.release();
music = null;
}
}

@Override
public void onClick(View v) {
startActivity(new Intent(UseActivityLife.this, ManyActivity_B.class));
}
}

public class ActivityTransValue_B extends Activity{

private TextView tv_value;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_transvalue_b);
tv_value = (TextView) findViewById(R.id.tv_value);

Intent intent = getIntent();
if(intent != null){
String name = intent.getStringExtra("name");
int age = intent.getIntExtra("age",0);
tv_value.setText("intent.putExtra传值:  "+"name:"+name+"——"+"age:"+age);
}
}

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.imooc.activitystudy.OneActivity" >

<TextView
android:id="@+id/tv_act"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Activity_A" />
<Button
android:layout_below="@id/tv_act"
android:id="@+id/btn_switchToB"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="跳转到Activity_B" />

</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.imooc.activitystudy.OneActivity" >

<TextView
android:id="@+id/tv_value"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<ImageView
android:layout_below="@id/tv_value"
android:id="@+id/im_value"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>

</RelativeLayout>