实战Android：通过BroadcastReceiver监听Home，电源Power，和音量变化Volume键

小鱼儿 2022-05-18 04:12 927阅读 0赞

上一个例子是采用AccessibilityService来实现按键的监听。这次我们采用BroadcastReceiver来完成按键的监听。

缺点：我尝试了一下，暂时还不知道如何停止按 键的默认行为，比如我确实监听到了电源按键，但却没法阻止此刻屏幕变黑的行为。先在这记下。以后找到解决办法再补充。

注意点：

1。监听Home键的相关字符串。

注意下边的注释，这几个字符串是Android系统已经内置好了的，必须是这样，比如你写成home\_key，就不会反应。

final String SYSTEM_DIALOG_REASON_KEY = "reason";//按下Home键
    final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey"; // 系统内置字符串，表示home键 == 长按Home键
    final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps"; // 系统内置字符串，停止键

2。监听Volume键的字符串。

volume键的IntentFilter和Home，Power键不一样，没有相关ACTION，我只找到了这个，确实能监听到音量按键，但假设已经达到最大音量或最小音量，再往极限调，音量不会变化，就监听不到了。

mIntentFilter = new IntentFilter();
    mIntentFilter.addAction("android.media.VOLUME_CHANGED_ACTION");

好了，下面先看监听输出，我的手机大致如此，

![70][]

源码如下，

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.spacesoftwares.spacecapture">
        <application
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:theme="@style/AppTheme">
            <activity
                android:name=".MainActivity"
                android:launchMode="singleTask">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
    
            <service
                android:name=".service.WhiteService"
                android:enabled="true"
                android:exported="false"
                />
        </application>
    </manifest>

MainActivity.java

package com.spacesoftwares.spacecapture;
    
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    
    import com.spacesoftwares.spacecapture.service.WhiteService;
    
    
    public class MainActivity extends AppCompatActivity {
    
        private Button mBtnWhite, mBtnStopWhite, mBtnExit;
    
        private final static String TAG = MainActivity.class.getSimpleName();
        private Intent whiteIntent;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            mBtnWhite = findViewById(R.id.btn_white);
            mBtnStopWhite = findViewById(R.id.btn_stop_white);
            mBtnExit = findViewById(R.id.btn_exit);
            setListener();
        }
    
        @Override
        protected void onDestroy() {
            super.onDestroy();
        }
    
        class ExitReceiver extends BroadcastReceiver {
            @Override
            public void onReceive(Context context, Intent intent) {
                MainActivity.this.finish();
            }
        }
    
        private void setListener(){
            OnClick onClick = new OnClick();
            mBtnWhite.setOnClickListener(onClick);
            mBtnStopWhite.setOnClickListener(onClick);
            mBtnExit.setOnClickListener(onClick);
        }
    
        private class  OnClick implements  View.OnClickListener{
            @Override
            public void onClick(View view) {
                int viewId = view.getId();
                switch(viewId){
                    case R.id.btn_white:
                        Log.i(TAG, "MAIN: btn_white");
                        if(null == whiteIntent)
                            whiteIntent = new Intent(MainActivity.this, WhiteService.class);
                        startService(whiteIntent);
                        break;
                    case R.id.btn_stop_white:
                        Log.i(TAG, "MAIN: btn_stop_white");
                        if(null != whiteIntent)
                           stopService(whiteIntent);
                    break;
                    case R.id.btn_exit:
                        Log.i(TAG, "MAIN: btn_exit");
                        if(null != whiteIntent)
                            stopService(whiteIntent);
                        finish();
                        break;
                }
            }
        }
    
    }

WhiteService.java

package com.spacesoftwares.spacecapture.service;
    
    import android.app.Notification;
    import android.app.NotificationChannel;
    import android.app.NotificationManager;
    import android.app.PendingIntent;
    import android.app.Service;
    import android.content.Context;
    import android.content.Intent;
    import android.graphics.Color;
    import android.os.Build;
    import android.os.IBinder;
    import android.provider.Settings;
    import android.support.annotation.Nullable;
    import android.support.v4.app.NotificationCompat;
    import android.util.Log;
    
    import com.spacesoftwares.spacecapture.MainActivity;
    import com.spacesoftwares.spacecapture.R;
    import com.spacesoftwares.spacecapture.key.HomeKeyObserver;
    import com.spacesoftwares.spacecapture.key.PowerKeyObserver;
    import com.spacesoftwares.spacecapture.key.VolumeKeyObserver;
    
    import java.io.IOException;
    import java.nio.channels.Channel;
    
    public class WhiteService extends Service {
    
        static public boolean isPowerKeyPressed = false;
    
        private final static String TAG = WhiteService.class.getSimpleName();
        private final static int FOREGROUND_ID = 1000;
        private Notification mNotification;
    
        /**
         * 参考:
         * 1 https://blog.csdn.net/q445697127/article/details/8432513
         * 2 https://blog.csdn.net/lfdfhl/article/details/9903693
         */
        private HomeKeyObserver mHomeKeyObserver;
        private PowerKeyObserver mPowerKeyObserver;
        private VolumeKeyObserver mVolumeKeyObserver;
    
        private void init() {
            mHomeKeyObserver = new HomeKeyObserver(this);
            mHomeKeyObserver.setHomeKeyListener(new HomeKeyObserver.OnHomeKeyListener() {
                @Override
                public void onHomeKeyPressed() {
                    Log.i(TAG,"----> 按下Home键");
                    System.out.println("----> 按下Home键");
                }
    
                @Override
                public void onHomeKeyLongPressed() {
                    Log.i(TAG,"----> 长按Home键");
                    System.out.println("----> 长按Home键");
                }
            });
            mHomeKeyObserver.startListen();
    
            //
            mPowerKeyObserver = new PowerKeyObserver(this);
            mPowerKeyObserver.setPowerKeyListener(new PowerKeyObserver.OnPowerKeyListener() {
                @Override
                public void onPowerKeyPressed() {
                    Log.i(TAG,"----> 按下电源键");
                    System.out.println("----> 按下电源键");
                    isPowerKeyPressed = true;
                }
            });
            mPowerKeyObserver.startListen();
    
            //
            mVolumeKeyObserver = new VolumeKeyObserver(this);
            mVolumeKeyObserver.setVolumeKeyListener(new VolumeKeyObserver.OnVolumeKeyListener() {
                @Override
                public void onVolumeKeyPressed() {
                    Log.i(TAG,"----> 按下电源键");
                    System.out.println("----> 按下电源键");
                }
            });
            mVolumeKeyObserver.startListen();
        }
    
        public WhiteService(){}
    
        @Nullable
        @Override
        public IBinder onBind(Intent intent) {
            //return null;
            throw new UnsupportedOperationException("Not yet implemented");
        }
    
        @Override
        public void onCreate() {
            Log.i(TAG, "WhiteService->onCreate");
            super.onCreate();
            init();
        }
    
        @Override
        public void onDestroy() {
            Log.i(TAG, "WhiteService->onDestroy");
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
            //if(null !=mNotification)
            {
                stopForeground(Service.STOP_FOREGROUND_REMOVE);
            }
    
            mHomeKeyObserver.stopListen();
            mPowerKeyObserver.stopListen();
            mVolumeKeyObserver.stopListen();
            super.onDestroy();
        }
    
        @Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            if(null != mNotification){
                Log.i(TAG, "WhiteService->onStartCommand->Notification exists");
                return super.onStartCommand(intent, flags, startId);
            }
    
            Log.i(TAG, "WhiteService->onStartCommand->Create Notification");
            //NotificationManager manager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
            //NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            String NOTIFICATION_CHANNEL_ID = "my_channel_id_01";
    
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "My Notifications", NotificationManager.IMPORTANCE_HIGH);
    
                // Configure the notification channel.
                notificationChannel.setDescription("Channel description");
                notificationChannel.enableLights(true);
                notificationChannel.setLightColor(Color.RED);
                notificationChannel.setVibrationPattern(new long[]{0, 1000, 500, 1000});
                notificationChannel.enableVibration(true);
    
                NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
                notificationManager.createNotificationChannel(notificationChannel);
            }
    
            NotificationCompat.Builder builder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
            builder.setSmallIcon(R.mipmap.ic_launcher);
            builder.setContentTitle("Foreground");
            builder.setContentText("Text shown on notification bar");
            builder.setContentInfo("Content Info");
            builder.setWhen(System.currentTimeMillis());
    
            Intent activityIntent = new Intent(this, MainActivity.class);
            PendingIntent pendingIntent = PendingIntent.getActivity(this, 1, activityIntent, PendingIntent.FLAG_UPDATE_CURRENT);
            builder.setContentIntent(pendingIntent);
            mNotification = builder.build();
            startForeground(FOREGROUND_ID, mNotification);
            return super.onStartCommand(intent, flags, startId);
        }
    }

HomeKeyOberver.java

package com.spacesoftwares.spacecapture.key;
    
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    
    import java.util.Objects;
    
    public class HomeKeyObserver {
        private Context mContext;
        private IntentFilter mIntentFilter;
        private OnHomeKeyListener mOnHomeKeyListener;
        private HomeKeyBroadcastReceiver mHomeKeyBroadcastReceiver;
    
        public HomeKeyObserver(Context context) {
            this.mContext = context;
        }
    
        //注册广播接收者
        public void startListen(){
            mIntentFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
            mHomeKeyBroadcastReceiver=new HomeKeyBroadcastReceiver();
            mContext.registerReceiver(mHomeKeyBroadcastReceiver, mIntentFilter);
            System.out.println("HomeKey----> 开始监听");
        }
    
        //取消广播接收者
        public void stopListen(){
            if (mHomeKeyBroadcastReceiver!=null) {
                mContext.unregisterReceiver(mHomeKeyBroadcastReceiver);
                System.out.println("HomeKey----> 停止监听");
            }
        }
    
        // 对外暴露接口
        public void setHomeKeyListener(OnHomeKeyListener homeKeyListener) {
            mOnHomeKeyListener = homeKeyListener;
        }
    
        // 回调接口
        public interface OnHomeKeyListener {
            void onHomeKeyPressed();
            void onHomeKeyLongPressed();
        }
    
        //广播接收者
        class HomeKeyBroadcastReceiver extends BroadcastReceiver{
            final String SYSTEM_DIALOG_REASON_KEY = "reason";
            //按下Home键
            final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey"; // 系统内置字符串，表示home键
            //长按Home键
            final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps"; // 系统内置字符串，停止键
            @Override
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
                if (Objects.equals(action, Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {
                    String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);
                    if (reason != null && mOnHomeKeyListener != null) {
                        if (reason.equals(SYSTEM_DIALOG_REASON_HOME_KEY)) {
                            mOnHomeKeyListener.onHomeKeyPressed();
                        } else if (reason.equals(SYSTEM_DIALOG_REASON_RECENT_APPS)) {
                            mOnHomeKeyListener.onHomeKeyLongPressed();
                        }
                    }
                }
            }
        }
    }

PowerKeyObserver.java

package com.spacesoftwares.spacecapture.key;
    
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.util.Log;
    
    import java.util.Objects;
    
    public class PowerKeyObserver {
        private String TAG_POWER = "PowerKey";
        private Context mContext;
        private IntentFilter mIntentFilter;
        private OnPowerKeyListener mOnPowerKeyListener;
        private PowerKeyBroadcastReceiver mPowerKeyBroadcastReceiver;
        public PowerKeyObserver(Context context) {
            this.mContext = context;
        }
    
        //注册广播接收者
        public void startListen(){
            mIntentFilter=new IntentFilter(Intent.ACTION_SCREEN_OFF);
            mPowerKeyBroadcastReceiver=new PowerKeyBroadcastReceiver();
            mContext.registerReceiver(mPowerKeyBroadcastReceiver, mIntentFilter);
            Log.i(TAG_POWER, "PowerKey----> 开始监听");
            System.out.println("PowerKey----> 开始监听");
        }
    
        //取消广播接收者
        public void stopListen(){
            if (mPowerKeyBroadcastReceiver!=null) {
                mContext.unregisterReceiver(mPowerKeyBroadcastReceiver);
                Log.i(TAG_POWER, "PowerKey----> 停止监听");
                System.out.println("PowerKey----> 停止监听");
            }
        }
    
        // 对外暴露接口
        public void setPowerKeyListener(OnPowerKeyListener powerKeyListener) {
            mOnPowerKeyListener = powerKeyListener;
        }
    
        // 回调接口
        public interface OnPowerKeyListener {
            void onPowerKeyPressed();
        }
    
        //广播接收者
        class PowerKeyBroadcastReceiver extends BroadcastReceiver{
            @Override
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
                if (Objects.equals(action, Intent.ACTION_SCREEN_OFF)) {
                    mOnPowerKeyListener.onPowerKeyPressed();
                    //abortBroadcast();
                }
            }
        }
    }

VolumeKeyObserver.java

package com.spacesoftwares.spacecapture.key;
    
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.util.Log;
    
    import java.util.Objects;
    
    public class VolumeKeyObserver {
        private String TAG_VOLUME = "VOLUME";
        private Context mContext;
        private IntentFilter mIntentFilter;
        private VolumeKeyObserver.OnVolumeKeyListener mOnVolumeKeyListener;
        private VolumeKeyObserver.VolumeKeyBroadcastReceiver mVolumeKeyBroadcastReceiver;
    
        public VolumeKeyObserver(Context context) {
            this.mContext = context;
        }
    
        //注册广播接收者
        public void startListen(){
            //mIntentFilter = new IntentFilter(Intent.ACTION_VOICE_COMMAND);
            mIntentFilter = new IntentFilter();
            mIntentFilter.addAction("android.media.VOLUME_CHANGED_ACTION");
            mVolumeKeyBroadcastReceiver=new VolumeKeyObserver.VolumeKeyBroadcastReceiver();
            mContext.registerReceiver(mVolumeKeyBroadcastReceiver, mIntentFilter);
            System.out.println("VolumeKey----> 开始监听");
        }
    
        //取消广播接收者
        public void stopListen(){
            if (mVolumeKeyBroadcastReceiver!=null) {
                mContext.unregisterReceiver(mVolumeKeyBroadcastReceiver);
                System.out.println("VolumeKey----> 停止监听");
            }
        }
    
        // 对外暴露接口
        public void setVolumeKeyListener(VolumeKeyObserver.OnVolumeKeyListener VolumeKeyListener) {
            mOnVolumeKeyListener = VolumeKeyListener;
        }
    
        // 回调接口
        public interface OnVolumeKeyListener {
            void onVolumeKeyPressed();
        }
    
        //广播接收者
        class VolumeKeyBroadcastReceiver extends BroadcastReceiver {
            @Override
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
                if (Objects.equals(action, "android.media.VOLUME_CHANGED_ACTION")) {
                    Log.i(TAG_VOLUME, "VolumeKey----> 监听到了音量调节");
                    System.out.println("VolumeKey----> 监听到了音量调节");
                }
            }
        }
    }

activity\_main.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        tools:context=".MainActivity">
    
        <Button
            android:id="@+id/btn_white"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/service_white" />
    
        <Button
            android:id="@+id/btn_stop_white"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/stop_white" />   
    
        <Button
            android:id="@+id/btn_exit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/exit" />
    
    </LinearLayout>

另外我也上传的完整的代码，可以直接下载运行，

[https://download.csdn.net/download/tanmx219/10571550][https_download.csdn.net_download_tanmx219_10571550]

[70]: /images/20220518/cb5d242015ea43259a695a7ba0e60b2e.png
[https_download.csdn.net_download_tanmx219_10571550]: https://download.csdn.net/download/tanmx219/10571550