广播接受者不仅可以通过清单文件来向系统注册,也可以通过代码来注册。并且有的广播必须通过代码来注册广播接受者。
- 锁屏和解锁广播
- 电量改变广播
打开屏幕和关闭屏幕
这里将广播接收者写在服务里面
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="18sp" android:text="开始播放" android:onClick="start"/> <Button android:id="@+id/stop" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="18sp" android:text="停止播放" android:onClick="stop"/> </LinearLayout>
Activity
package xidian.dy.com.chujia; import android.content.Intent; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; public class MainActivity extends AppCompatActivity { Intent service; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); service = new Intent(this, MyService.class); } public void start(View v){ startService(service); } public void stop(View v){ stopService(service); } }
服务
在服务开启的时候注册广播,在服务销毁的时候销毁广播
package xidian.dy.com.chujia; import android.app.Service; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.os.IBinder; import android.support.annotation.Nullable; import android.util.Log; /** * Created by dy on 2016/7/12. */ class MyReceiver extends BroadcastReceiver{ @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if(action.equals(Intent.ACTION_SCREEN_OFF)) Log.i(this.getClass().getName(), "屏幕关闭"); if(action.equals(Intent.ACTION_SCREEN_ON)) Log.i(this.getClass().getName(), "屏幕点亮"); } } public class MyService extends Service { MyReceiver ms = new MyReceiver(); @Override public void onCreate() { super.onCreate(); IntentFilter filter = new IntentFilter(); filter.addAction(Intent.ACTION_SCREEN_OFF); filter.addAction(Intent.ACTION_SCREEN_ON); registerReceiver(ms, filter); } @Nullable @Override public IBinder onBind(Intent intent) { return null; } @Override public void onDestroy() { super.onDestroy(); unregisterReceiver(ms); } }
清单文件
在清单文件中只需要注册服务即可
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="xidian.dy.com.chujia"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity" android:label="主界面"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name=".MyService" /> </application> </manifest>