最近在做视频播放器的时候,遇到一个问题,在用户播放视频然后锁屏之后,视频播放器仍然在继续播放,遇到类似手机系统状态改变的问题的时候,首先想到了广播(don't call me,i will call you);在网上搜罗了一个方法,做个总结;

public class ScreenListener {    private Context mContext;    private ScreenBroadcastReceiver mScreenReceiver;    private ScreenStateListener mScreenStateListener;    public ScreenListener(Context context) {        mContext = context;        mScreenReceiver = new ScreenBroadcastReceiver();    }    /**     * screen状态广播接收者     */    private class ScreenBroadcastReceiver extends BroadcastReceiver {        private String action = null;        @Override        public void onReceive(Context context, Intent intent) {            action = intent.getAction();            if (Intent.ACTION_SCREEN_ON.equals(action)) { // 开屏                mScreenStateListener.onScreenOn();            } else if (Intent.ACTION_SCREEN_OFF.equals(action)) { // 锁屏                mScreenStateListener.onScreenOff();            } else if (Intent.ACTION_USER_PRESENT.equals(action)) { // 解锁                mScreenStateListener.onUserPresent();            }        }    }    /**     * 开始监听screen状态     *      * @param listener     */    public void begin(ScreenStateListener listener) {        mScreenStateListener = listener;        registerListener();        getScreenState();    }    /**     * 获取screen状态     */    private void getScreenState() {        PowerManager manager = (PowerManager) mContext                .getSystemService(Context.POWER_SERVICE);        if (manager.isScreenOn()) {            if (mScreenStateListener != null) {                mScreenStateListener.onScreenOn();            }        } else {            if (mScreenStateListener != null) {                mScreenStateListener.onScreenOff();            }        }    }    /**     * 停止screen状态监听     */    public void unregisterListener() {        mContext.unregisterReceiver(mScreenReceiver);    }    /**     * 启动screen状态广播接收器     */    private void registerListener() {        IntentFilter filter = new IntentFilter();        filter.addAction(Intent.ACTION_SCREEN_ON);        filter.addAction(Intent.ACTION_SCREEN_OFF);        filter.addAction(Intent.ACTION_USER_PRESENT);        mContext.registerReceiver(mScreenReceiver, filter);    }    public interface ScreenStateListener {
   // 返回给调用者屏幕状态信息        public void onScreenOn();        public void onScreenOff();        public void onUserPresent();    }}

在上面的代码中,用到了动态注册广播,在需要监听屏幕状态的activity中,当不需要监听的时候,如activity finish的时候,使用unregisterListener解除广播监听;

下面是在Activity中调用;

ScreenListener l = new ScreenListener(this);        l.begin(new ScreenStateListener() {            @Override            public void onUserPresent() {                Log.e("onUserPresent", "onUserPresent");            }            @Override            public void onScreenOn() {                Log.e("onScreenOn", "onScreenOn");            }            @Override            public void onScreenOff() {                Log.e("onScreenOff", "onScreenOff");            }        });

通过以上步骤即实现了对屏幕状态的监听.