如何动态监听值，保持UI同步

importandroid.database.ContentObserver;

getContentResolver().registerContentObserver(Settings.Global.getUriFor(DOZE_WHATSAPP_MODE),false,

mWhatsAppModeObserver);

getContentResolver().unregisterContentObserver(mWhatsAppModeObserver);

    private ContentObserver mWhatsAppModeObserver = new ContentObserver(
            new Handler()) {
        public void onChange(boolean selfChange, Uri uri) {
            Log.d(TAG, "mWhatsAppModeObserver:" + uri.toString());
            if (uri.toString().equals(mWhatsappUri)) {
                Log.d(TAG, "mWhatsAppModeObserver onChange begin ----->");
                boolean isWhatsapp = mPresenter.isWhatsAppMode();
                Log.d(TAG, "mWhatsAppModeObserver isWhatsapp:" + isWhatsapp);
                mWhatsAppSwitch.setChecked(isWhatsapp);
                mTvWhatsAppSwitchTip.setText(isWhatsapp ? R.string.feature_on : R.string.feature_off);
                Log.d(TAG, "mWhatsAppModeObserver onChange end----->");
            }
        }
    };