android:进入活动时摆脱焦点

<uses-permission android:name="android.permission.MEDIA_BUTTON" />

private BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action.equals(Intent.ACTION_MEDIA_BUTTON)) {
            KeyEvent event = (KeyEvent)intent.getExtras().get(Intent.EXTRA_KEY_EVENT);
            if (event != null) {
                if (event.getAction() == KeyEvent.ACTION_DOWN) {
                    // 处理按下事件
                } else if (event.getAction() == KeyEvent.ACTION_UP) {
                    // 处理释放事件
                }
            }
        }
    }
};

ViewTreeObserver viewTreeObserver = findViewById(R.id.view_root_id);
viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        // 获取焦点
        View currentFocus = getCurrentFocus();
        if (currentFocus != null) {
            currentFocus.setOnFocusChangeListener(new View.OnFocusChangeListener() {
                @Override
                public void onFocusChange(View view, boolean b) {
                    // 处理焦点变化
                }
            });
        }
    }
});

View currentFocus = findViewById(R.id.view_id);
currentFocus.setOnFocusChangeListener(new View.OnFocusChangeListener() {
    @Override
    public void onFocusChange(View view, boolean b) {
        // 处理焦点变化
    }
});