Question

我正在使用Fragments做一个简单的3页应用程序，页面之间有幻灯片。

但是现在，我有3个片段，但应用程序只能使用de 2和3进行滑动。

必须1 - ＆gt; 2 - ＆gt; 3，但3 - ＆gt; 2 - ＆gt; 3。如果你知道我想说的话。

这是我的代码

public class main extends Activity {



public static SectionsPagerAdapter mSectionsPagerAdapter;
public static Boolean init = true;


static ViewPager mViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mSectionsPagerAdapter = new SectionsPagerAdapter(getFragmentManager());

    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);
}



public class SectionsPagerAdapter extends FragmentPagerAdapter {

   [...]
}


public static class PlaceholderFragment extends Fragment {

    private static final String ARG_SECTION_NUMBER = "section_number";
    private static int ARG_NUMBER = 0;



    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        ARG_NUMBER = sectionNumber;
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = new View(this.getActivity());

   // THE PROBLEM SHOULD COME FROM HERE

            switch (ARG_NUMBER) {
                case 1:
                    rootView = inflater.inflate(R.layout.fragment_main, container, false);
                    break;
                case 2:
                    rootView = inflater.inflate(R.layout.fragment_map, container, false);
                    break;
                case 3:
                    rootView = inflater.inflate(R.layout.profile, container, false);
                    break;
            }


        return rootView;
    }
}
}

所以，如果有人有想法......谢谢！

编辑：

    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 + 1);
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
            case 0:
                return getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return getString(R.string.title_section2).toUpperCase(l);
            case 2:
                return getString(R.string.title_section3).toUpperCase(l);
        }
        return null;
    }
}

Answer 1

您应该use arguments片段instead of设置ARG_NUMBER = sectionNumber

您的代码应如下所示：

public static class PlaceholderFragment extends Fragment {

    private static final String ARG_SECTION_NUMBER = "section_number";
    private int ARG_NUMBER = 0;



    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = new View(this.getActivity());

         ARG_NUMBER = getArguments().getInt(ARG_SECTION_NUMBER, 0);

            switch (ARG_NUMBER) {
                case 1:
                    rootView = inflater.inflate(R.layout.fragment_main, container, false);
                    break;
                case 2:
                    rootView = inflater.inflate(R.layout.fragment_map, container, false);
                    break;
                case 3:
                    rootView = inflater.inflate(R.layout.profile, container, false);
                    break;
            }


        return rootView;
    }
}

注意：如果Switch case不允许非常量值，请使用if-else梯形图。

Android幻灯片片段不会全部加载

1 个答案: