How to set a ViewPager inside a Fragment

问题

I need to place a ViewPager inside of a fragment, but I have two fragments, Fragment 1 is my MENU, and Fragment 2 I want to use as a ViewPagerIndicator.

But a fragment can\'t have another fragment... what do I need to do for that?

$\"enter$

回答1:

Starting in Android 4.2, there are nested fragments.http://developer.android.com/about/versions/android-4.2.html#NestedFragments The support library now also includes support for this for older Android versions.

So you can do something like this:

@Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    ViewPager mViewPager = (ViewPager) view.findViewById(R.id.viewPager);
    mViewPager.setAdapter(new MyAdapter(getChildFragmentManager()));
    }

Full implementation available here: https://github.com/marcoRS/nested-fragments/tree/master/src/com/burnside/digital/nestedfragments

回答2:

You must use getChildFragmentManager() instead of getSupportFragmentManager() to get the FragmentManger inside a Fragment. But you should not use FragmentStatePagerAdapter rather than FragmentPagerAdapter.

回答3:

it is possible. try to do this code view_pager_fragment.xml file

<android.support.design.widget.AppBarLayout
    android:id="@+id/appBarLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.TabLayout
        android:id="@+id/tab"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

ViewPagerFragment

ViewPager viewPager;
TabLayout tabLayout;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.tracks, container, false);

    viewPager = (ViewPager) view.findViewById(R.id.viewpager);
    tabLayout = (TabLayout) view.findViewById(R.id.tab);

    return view;
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    setupViewPager(viewPager);
    tabLayout.setupWithViewPager(viewPager);

    tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

private void setupViewPager(ViewPager viewPager) {
    ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager());``

    viewPagerAdapter.addFragment(new FirstFragment(), "First");
    viewPagerAdapter.addFragment(new SecoundFragment(), "Secound");
    viewPagerAdapter.addFragment(new LoginFragment(), "Login");

    viewPager.setAdapter(viewPagerAdapter);
}

private class ViewPagerAdapter extends FragmentPagerAdapter {

    List<Fragment> fragmentList = new ArrayList<>();
    List<String> fragmentTitles = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    @Override
    public Fragment getItem(int position) {
        return fragmentList.get(position);
    }

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

    @Override
    public CharSequence getPageTitle(int position) {
        return fragmentTitles.get(position);
    }

    public void addFragment(Fragment fragment, String name) {
        fragmentList.add(fragment);
        fragmentTitles.add(name);
    }
}

回答4:

Just use getChildFragmentManager() instead of getSupportFragmentManager() inside Fragments.

Inside Fragments

new ViewPagerAdapter(getChildFragmentManager());

Inside Activity

new ViewPagerAdapter(getSupportFragmentManager());

Simple Code

`fragment_sample.xml` layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tablayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

</LinearLayout>

`SampleFragment.java` class

public class SampleFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View fragmentView = inflater.inflate(R.layout.fragment_sample, container, false);
        return fragmentView;
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        // find views by id
        ViewPager viewPager = view.findViewById(R.id.viewpager);
        TabLayout tabLayout = view.findViewById(R.id.tablayout);

        // attach tablayout with viewpager
        tabLayout.setupWithViewPager(viewPager);

        ViewPagerAdapter adapter = new ViewPagerAdapter(getChildFragmentManager());

        // add your fragments
        adapter.addFrag(new SampleFragment(), "Tab1");
        adapter.addFrag(new SampleFragment2(), "Tab2");
        adapter.addFrag(new SampleFragment3(), "Tab3");

        // set adapter on viewpager
        viewPager.setAdapter(adapter);
    }
}

`ViewPagerAdapter.java` class

public class ViewPagerAdapter extends FragmentStatePagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

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

    @Override
    public CharSequence getPageTitle(int position) {
        return mFragmentTitleList.get(position);
    }

    public void addFrag(Fragment fragment) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add("");
    }

    public void addFrag(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }
}

Important Related Links

Difference between getSupportFragmentManager() and getChildFragmentManager()?
getSupportFragmentManager() versus getFragmentManager() in android 3.0+
Difference between FragmentPagerAdapter and FragmentStatePagerAdapter

回答5:

With the Android Support V4 library, you can add a fragment inside another fragment. Try to use it, it may can resolve your problem.

回答6:

After Read some examples, you cant have a FragmentActivity inside a fragmentActivity. Is not necesary to have two fragments and this need be a FragmentPageAdapter... i only need to do this.

<android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="0px"
        android:layout_weight="1" >
</android.support.v4.view.ViewPager>

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0"
        android:gravity="center"
        android:measureWithLargestChild="true"
        android:orientation="horizontal" >

<Button
            android:id="@+id/first"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="First" >
        </Button>

<Button
            android:id="@+id/last"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Last" >
</Button>
</LinearLayout>

Source: http://www.truiton.com/2013/05/android-fragmentpageradapter-example/

来源：https://stackoverflow.com/questions/19073541/how-to-set-a-viewpager-inside-a-fragment

标签

android

android-fragments

android-viewpager

android-nested-fragment