Android中双击返回键退出应用

Android中双击返回键退出程序

[b]1.在MyAppliction中(继承Application)[/b]

//运用list来保存们每一个activity是关键
private List<Activity> mList = new LinkedList<Activity>();
//为了实现每次使用该类时不创建新的对象而创建的静态对象
private static MyApplication instance;

//构造方法
public MyApplication() {
}

//实例化一次
public synchronized static MyApplication getInstance() {
if (null == instance) {
instance = new MyApplication();
}
return instance;
}

//添加要退出的Activity
public void addActivity(Activity activity) {
mList.add(activity);
}

//关闭每一个list内的activity
public void exit() {
try {
for (Activity activity : mList) {
if (activity != null)
activity.finish();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
System.exit(0);
}
}

//杀进程
public void onLowMemory() {
super.onLowMemory();
System.gc();
}

2.在你需要的关闭的Activity的onCreact()中加入

MyApplication.getInstance().addActivity(this);

3.你需要双击返回退出的界面加上

/**
* 两次返回退出
*/
private long mExitTime;

public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if ((System.currentTimeMillis() - mExitTime) > 3000) {
Toast.makeText(this, "再按一次退出程序", Toast.LENGTH_SHORT).show();
mExitTime = System.currentTimeMillis();
} else {
MyApplication.getInstance().exit();
}
return true;
}
return super.onKeyDown(keyCode, event);
}