/**
     * 是否联网
     *
     * @return
     */
    public static boolean isConnected(Context context) {
        ConnectivityManager connManager = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connManager == null)
            return false;
        NetworkInfo info = connManager.getActiveNetworkInfo();
        if (info != null && info.isAvailable()) {
            return true;
        }
        return false;
    }