android samsung note3 device not found

descriptiong :

android  samsung note3 　device not found

solution:

usb link by PTP, DONE!

(be curiosly: WHY NOT MTP??

notifyDataSetChanged

    /**
     * Notifies the attached observers that the underlying data has been changed
     * and any View reflecting the data set should refresh itself.
     */
    public void notifyDataSetChanged() {
        mDataSetObservable.notifyChanged();
    }