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Android Back Home键监听
Android Back Home键监听
Back键的监听
对于Back键的监听比较容易,可以在多个系统回调处拦截,比如在activity的下列方法中都可以收到Back键按下的事件:
@Override public void onBackPressed() { // super.onBackPressed();//注释掉这行,back键不退出activity Log.i(LOG_TAG, "onBackPressed"); } @Override public boolean dispatchKeyEvent(KeyEvent event) { Log.i(LOG_TAG, "dispatchKeyEvent: keyCode -- " + event.getKeyCode()); return super.dispatchKeyEvent(event); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { Log.i(LOG_TAG, "onKeyDown: keyCode -- " + keyCode); switch (keyCode) { case KeyEvent.KEYCODE_BACK: Log.i(LOG_TAG, "KeyEvent.KEYCODE_BACK"); break; case KeyEvent.KEYCODE_MENU: Log.i(LOG_TAG, "KeyEvent.KEYCODE_MENU"); break; case KeyEvent.KEYCODE_HOME: Log.i(LOG_TAG, "KeyEvent.KEYCODE_HOME"); // 收不到 break; case KeyEvent.KEYCODE_APP_SWITCH: Log.i(LOG_TAG, "KeyEvent.KEYCODE_APP_SWITCH"); // 收不到 break; default: break; } return super.onKeyDown(keyCode, event); }
Home键的广播监听
对于Home键的监听不是那么容易,因为Home键可以将程序退出放在后台,所以这个事件是直接分发给系统,系统接收到之后做相应处理,Home键的事件不是直接传递到应用里面.所以在上述监听Back键的代码中,相应的回调中是收不到Home键的事件的.
参考文后的博客链接,对Home键的监听主要通过注册广播接收器实现,拦截让窗口关闭的系统动作,然后根据Intent里面的具体参数,分析当前到底是Home键, 应用切换键,还是其他功能按键.
接收器实现如下:
package com.mengdd.hellohome;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;public class HomeWatcherReceiver extends BroadcastReceiver { private static final String LOG_TAG = "HomeReceiver"; private static final String SYSTEM_DIALOG_REASON_KEY = "reason"; private static final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps"; private static final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey"; private static final String SYSTEM_DIALOG_REASON_LOCK = "lock"; private static final String SYSTEM_DIALOG_REASON_ASSIST = "assist"; @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); Log.i(LOG_TAG, "onReceive: action: " + action); if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) { // android.intent.action.CLOSE_SYSTEM_DIALOGS String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY); Log.i(LOG_TAG, "reason: " + reason); if (SYSTEM_DIALOG_REASON_HOME_KEY.equals(reason)) { // 短按Home键 Log.i(LOG_TAG, "homekey"); } else if (SYSTEM_DIALOG_REASON_RECENT_APPS.equals(reason)) { // 长按Home键 或者 activity切换键 Log.i(LOG_TAG, "long press home key or activity switch"); } else if (SYSTEM_DIALOG_REASON_LOCK.equals(reason)) { // 锁屏 Log.i(LOG_TAG, "lock"); } else if (SYSTEM_DIALOG_REASON_ASSIST.equals(reason)) { // samsung 长按Home键 Log.i(LOG_TAG, "assist"); } } }}注意不同手机的按键不同,所以需要对不同理由做区分.
Home键监听广播注册
广播接收器的注册有两种方式,一种是静态注册,即写在manifest里面声明;另一种是动态注册,即在Java代码里面注册.
上面对Home键实现监听的这个receiver,静态注册如下:
<receiver android:name="com.mengdd.hellohome.HomeWatcherReceiver" > <intent-filter> <action android:name="android.intent.action.CLOSE_SYSTEM_DIALOGS" /> </intent-filter> </receiver>
但是发现静态注册不起作用,即收不到onReceive回调.
采用动态注册:
private static HomeWatcherReceiver mHomeKeyReceiver = null; private static void registerHomeKeyReceiver(Context context) { Log.i(LOG_TAG, "registerHomeKeyReceiver"); mHomeKeyReceiver = new HomeWatcherReceiver(); final IntentFilter homeFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS); context.registerReceiver(mHomeKeyReceiver, homeFilter); } private static void unregisterHomeKeyReceiver(Context context) { Log.i(LOG_TAG, "unregisterHomeKeyReceiver"); if (null != mHomeKeyReceiver) { context.unregisterReceiver(mHomeKeyReceiver); } }
在Activity的onResume和onPause里面分别调用:
@Override protected void onResume() { super.onResume(); registerHomeKeyReceiver(this); } @Override protected void onPause() { unregisterHomeKeyReceiver(this); super.onPause(); }当然也可以根据需要在其他合适的时机注册和注销.
参考资料
http://blog.csdn.net/way_ping_li/article/details/8953622
Android Back Home键监听
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