private static final String SYSTEM_DIALOG_REASON_KEY = "reason";
    private static final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps";
    private static final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";
    private static final String SYSTEM_DIALOG_REASON_LOCK = "lock";
    private static final String SYSTEM_DIALOG_REASON_ASSIST = "assist";
    private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.i(TAG, "onReceive: action: " + action);

            if (Intent.ACTION_CLOSE_SYSTEM_DIALOGS.equals(action)) {
                // android.intent.action.CLOSE_SYSTEM_DIALOGS == action
                String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);

                if (SYSTEM_DIALOG_REASON_HOME_KEY.equals(reason)) {
                    // 短按 Home 鍵
                    Log.i(TAG, "reason: homekey");
                } else if (SYSTEM_DIALOG_REASON_RECENT_APPS.equals(reason)) {
                    // 長按 Home 鍵或者 Recent 鍵
                    Log.i(TAG, "reason: recentapps");
                } else if (SYSTEM_DIALOG_REASON_LOCK.equals(reason)) {
                    // 鎖屏
                    Log.i(TAG, "reason: lock");
                } else if (SYSTEM_DIALOG_REASON_ASSIST.equals(reason)) {
                    // Samsung 長按 Home 鍵
                    Log.i(TAG, "reason: assist");
                } else {
                    Log.i(TAG, "reason: " + reason);
                }
            }
        }
    };

    private IntentFilter mIntentFilter;


        mIntentFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        registerReceiver(mBroadcastReceiver, mIntentFilter);

        if (null != mBroadcastReceiver) {
            unregisterReceiver(mBroadcastReceiver);
        }