BroadcastReceiver之实现锁屏解锁样例
Posted gavanwanggw
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好久没有写android的小样例了,因为前几天写了一篇关于Intent.Action的文章(http://blog.csdn.net/ljphhj/article/details/38796739)。有朋友私信问我关于ACTION_SCREEN_ON和ACTION_SCREEN_OFF还有ACTION_USER_PRESENT三个Action的使用方法,因为作为一个总结博文,当时并没有具体讲,ACTION_SCREEN_ON和ACTION_SCREEN_OFF仅仅能通过动态注冊的方式(代码内context.register和unregister)。而ACTION_USER_PRESENT则是动态、静态注冊两种方式都能够。
以下我们通过这个锁屏、解锁相关的BroadcastReceiver来了解一下。
package cn.panghu.activitys; import com.example.broadcastsappdemo.R; import android.app.Activity; import android.app.KeyguardManager; import android.app.KeyguardManager.KeyguardLock; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.os.Bundle; import android.os.PowerManager; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup.LayoutParams; import android.widget.Button; import android.widget.LinearLayout; import android.widget.TextView; import android.widget.Toast; public class ScreenLockedActivity extends Activity{ private ScreenBroadcastReceiver screenBroadcastReceiver = null; private Context context = null; private Button lockedScreenBtn = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); context = getApplicationContext(); setContentView(R.layout.screen_lock_layout); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); //注冊这个广播 registerScreenBroadcastReceiver(); } private void registerScreenBroadcastReceiver() { screenBroadcastReceiver = new ScreenBroadcastReceiver(); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction(Intent.ACTION_SCREEN_OFF);//当屏幕锁屏的时候触发 intentFilter.addAction(Intent.ACTION_SCREEN_ON);//当屏幕解锁的时候触发 intentFilter.addAction(Intent.ACTION_USER_PRESENT);//当用户又一次唤醒手持设备时触发 context.registerReceiver(screenBroadcastReceiver, intentFilter); Log.i("screenBR", "screenBroadcastReceiver注冊了"); } //重写广播 class ScreenBroadcastReceiver extends BroadcastReceiver{ @Override public void onReceive(Context context, Intent intent) { String strAction = intent.getAction(); if (Intent.ACTION_SCREEN_OFF.equals(strAction)){ //屏幕锁屏 Log.i("screenBR", "屏幕锁屏:ACTION_SCREEN_OFF触发"); Toast.makeText(context, "锁屏了", Toast.LENGTH_SHORT).show(); }else if (Intent.ACTION_SCREEN_ON.equals(strAction)){ //屏幕解锁(实际測试效果,不能用这个来推断解锁屏幕事件) //【因为这个是解锁的时候触发。而解锁的时候广播还未注冊】 Log.i("screenBR", "屏幕解锁:ACTION_SCREEN_ON触发"); Toast.makeText(context, "解锁了", Toast.LENGTH_SHORT).show(); }else if (Intent.ACTION_USER_PRESENT.equals(strAction)){ //屏幕解锁(该Action能够通过静态注冊的方法注冊) //在解锁之后触发的,广播已注冊 Log.i("screenBR", "屏幕解锁:ACTION_USER_PRESENT触发"); Toast.makeText(context, "解锁了", Toast.LENGTH_SHORT).show(); }else{ //nothing } } } @Override protected void onPause() { // TODO Auto-generated method stub super.onPause(); context.unregisterReceiver(screenBroadcastReceiver); Log.i("screenBR", "screenBroadcastReceiver取消注冊了"); } }
因为是静态注冊的方式,所以大家可能会认为那我要怎么让它长久地监听这锁屏、解锁屏幕的广播呢?
首先我们再次强调ACTION_SCREEN_ON和ACTION_SCREEN_OFF仅仅能通过动态注冊的方式(代码内context.register和unregister),而ACTION_USER_PRESENT则是动态、静态注冊两种方式都能够。
那么我们的突破口便是:我们能够动态地注冊一个关于屏幕解锁后(ACTION_USER_PRESENT)的广播者。而且在这个广播的onReceive方法中实现我们要做的一些操作。
比如我们能够开启一个Service服务。用于注冊我们所想要的这个Broadcast Receiver
1.在Service中定义receiver
- private BroadcastReceiver mScreenFilterReceiver = new BroadcastReceiver() {
- public void onReceive(Context context, Intent intent) {
- if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
- //做要求的处理
- }else if(intent.getAction().equals(Intent.ACTION_SCREEN_OFF)){
- }
- }
- };
2.在Service的onCreate中定义IntentFilter及注冊receiver
- IntentFilter ScreenFilter = new IntentFilter();
- ScreenFilter.addAction(Intent.ACTION_SCREEN_ON);
- ScreenFilter.addAction(Intent.ACTION_SCREEN_OFF);
- registerReceiver(mScreenFilterReceiver, ScreenFilter);
3.在Service的onDestroy中要反注冊这个receiver。
- unregisterReceiver(mScreenFilterReceiver);
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