Android 判斷Intent action是否可以被找到

    public static boolean isIntentAvailable(Context context, String action) {
        final PackageManager packageManager = context.getPackageManager();
        final Intent intent = new Intent(action);
        List<ResolveInfo> list =
                packageManager.queryIntentActivities(intent,
                        PackageManager.MATCH_DEFAULT_ONLY);
        return list.size() > 0;
    }

 if(isIntentAvailable(getActivity(),QRCODE_ACTICON)){
                    optionMenuOn = true;
                    checkOptionMenu();
                }