在活动中随时退出程序

public class ActivityCollector {
public static List<Activity> activities = new ArrayList<Activity>();
/*
* 添加活动
*/
public static void addActivity(Activity activity){
activities.add(activity);
}
/*
*删除活动
*/
public static void removeActivity(Activity activity){
activities.remove(activity);
}
/*
* 销毁所有活动
*/
public static void finishAll(){
for (Activity activity : activities) {
if(!activity.isFinishing()){
activity.finish();
}
}
}
}

public class BaseActivity extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
ActivityCollector.addActivity(this);
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
ActivityCollector.removeActivity(this);
}
}

public class ThirdActivity extends BaseActivity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
Log.d("ThirdActivity", "Task id is " + getTaskId());
setContentView(R.layout.activity_third);
Button button = (Button) findViewById(R.id.button3);
button.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
ActivityCollector.finishAll();
}
});

}
}