android - fragment 重复选项卡布局

Question

我有一个 fragment ，其中有三个选项卡，在我从另一个 Activity 回到 HomeFragment 后，它是一样的，我有重复的布局

如果我做错了什么，请告诉我？

HomeFragment.class

    public class HomeFragment extends Fragment {

   public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


    }
    public View onCreateView(LayoutInflater inflater , ViewGroup container ,
                                 Bundle savedInstanceState) {

            View rootView = inflater.inflate(R.layout.fragment_home,container,false);

            // [Start Tabs]
            Toolbar toolbar = (Toolbar) rootView.findViewById(R.id.toolbar_fragment);
            //toolbar.setNavigationIcon(android.R.drawable.ic_menu_preferences);


            ((AppCompatActivity) getActivity()).setSupportActionBar(toolbar);

            ((AppCompatActivity) getActivity()).getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);

            ((AppCompatActivity) getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true);

            viewPager = (ViewPager) rootView.findViewById(R.id.fragmetn_viewpager);

            setupViewPager(viewPager);

            tabLayout = (TabLayout) rootView.findViewById(R.id.tabs_fragment);
            tabLayout.setupWithViewPager(viewPager);
            //[*End Tab ]

            return rootView;
        }


        private void setupViewPager(ViewPager viewPager){
            ViewPagerAdapter adapter = new ViewPagerAdapter(getChildFragmentManager());
            adapter.notifyDataSetChanged();
            adapter.addFragment(new Tab1Fragment() , "Tab1");
            adapter.addFragment(new Tab2Fragment() , "Tab2");
            adapter.addFragment(new Tab3Fragment() , "Tab3");
            viewPager.setAdapter(adapter);
        }
    }

Answer 1

尝试如下:

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


    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        app:tabGravity="fill"
        app:tabMode="scrollable"
        android:background="@color/material_blue_grey_800"
        app:tabIndicatorColor="@color/orange"
        app:tabSelectedTextColor="@color/orange"
        app:tabTextColor="@color/white"
        android:layout_width="match_parent"
        android:singleLine="true"
        android:layout_height="wrap_content">

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

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

    </android.support.v4.view.ViewPager>

</LinearLayout>

和:

public class TabFragment extends Fragment {

    public TabLayout tabLayout;
    public ViewPager viewPager;

    private static int currentItem = 0;
    MyAdapter adapter;

    public static TabFragment newInstance(int someInt) {
        TabFragment frag = new TabFragment();
        Bundle args = new Bundle();
        args.putInt("tab", someInt);
        frag.setArguments(args);
        return frag;
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("currentItem", viewPager.getCurrentItem());
    }

    public static TabFragment newInstance() {
        TabFragment frag = new TabFragment();

        return frag;
    }
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        adapter=new MyAdapter(getChildFragmentManager());
        currentItem=getArguments() != null ? getArguments().getInt("tab") : 0;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        /**
         *Inflate tab_layout and setup Views.
         */
            View x =  inflater.inflate(R.layout.tab_layout,null);
            tabLayout = (TabLayout) x.findViewById(R.id.tabs);
            viewPager = (ViewPager) x.findViewById(R.id.viewpager);

        /**
         *Set an Adapter for the View Pager
         */
        if (adapter==null) adapter=new MyAdapter(getChildFragmentManager());
        viewPager.setAdapter(adapter);
        viewPager.setCurrentItem( currentItem);

        /**
         * Now , this is a workaround ,
         * The setupWithViewPager doesn't work without the Runnable .
         * Maybe a Support Library Bug .
         */

        tabLayout.post(new Runnable() {
            @Override
            public void run() {
                    tabLayout.setupWithViewPager(viewPager);
                   }
        });

        return x;

    }

class MyAdapter extends FragmentPagerAdapter {

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

        /**
         * Return fragment with respect to Position .
         */

        @Override
        public Fragment getItem(int position)
        {
          switch (position){
              case 0 : return new Tab1Fragment();
              case 1 : return new Tab2Fragment();
              case 2 : return new Tab3Fragment();
          }
        return null;
        }

        @Override
        public int getCount() {
            return 3;
        }


        @Override
        public CharSequence getPageTitle(int position) {

            switch (position){
                case 0 :
                    return "Tab1";
                case 1 :
                    return "Tab2";
                case 2 :
                    return "Tab3";
            }
                return null;
        }
    }