从arraylist获取值到viewpager片段

Question

我正在尝试使用viewpager进行此主题选择。我创建了一个静态arraylist对象，并在此活动中使用它与viewpager。但无法妥善管理它。它是从位置+ 1值设置工具栏和状态颜色，其余的正常工作。背景，文本颜色和名称是正确的，但工具栏和状态栏具有下一次迭代的值。

 /**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String COLORSET_POS = "list_pos";
    TextView nick,post,countdown;
    FrameLayout frameLayout;
    Toolbar toolbar;

    Button select;
    public PlaceholderFragment() {
    }

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(COLORSET_POS, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.colorset_preview_layout, container, false);
        int pos = getArguments().getInt(COLORSET_POS);
        nick = (TextView) rootView.findViewById(R.id.nick);
        post = (TextView) rootView.findViewById(R.id.post);
        countdown = (TextView) rootView.findViewById(R.id.countdown);
        frameLayout = (FrameLayout) rootView.findViewById(R.id.frame);
        toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
        select = (Button) rootView.findViewById(R.id.select);
        if(HelperClass.colorSetArrayList != null)
            setColors(HelperClass.colorSetArrayList.get(pos).colorSet());
        Toast.makeText(getActivity(), "Position " + pos + " name " + HelperClassHelperClass.colorSetArrayList.get(pos).getName(), Toast.LENGTH_SHORT).show();
        return rootView;
    }
    synchronized void setColors(ColorSet colorSet){
        toolbar.setSubtitle(String.format(getString(R.string.online_count), new Random().nextInt(20)));
            if (colorSet != null) {
                nick.setTextColor(colorSet.textcolor());
                post.setTextColor(colorSet.textcolor());
                countdown.setTextColor(colorSet.textcolor());
                frameLayout.setBackgroundColor(colorSet.backgroundcolor());
                toolbar.setBackgroundColor(colorSet.primarycolor());
                nick.setText(.getUsername());
                select.setTextColor(colorSet.textcolor());
                if(colorSet.getName()!=null) post.setText(colorSet.getName());
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                    getActivity().getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
                    getActivity().getWindow().setStatusBarColor(colorSet.primarydarkcolor());
                }
            }

    }
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        return PlaceholderFragment.newInstance(position);
    }

    @Override
    public int getCount() {
        return HelperClass.colorSetArrayList.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {
        if(HelperClass.colorSetArrayList==null)
            return "null";
        else return HelperClass.colorSetArrayList.get(position).getName();
}
}