在活動中隨時退出程序

新建一個ActivityCollector類作爲活動管理類

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

然後新建BaseActivity類作爲所有活動的繼承類

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();
			}
		});

	}
}

這樣就可以隨時隨地退出程序了