4.8.3 在 一个 Fragment 里面实现ViewPager 和TabLayout 进行联动

4.8.3 ViewPager 和TabLayout 进行联动

首先在布局里面是一个LinearLayout，然后是TabLayout ，记着这个TabLayout 必须要是全部的路径，然后是ViewPager的

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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
    <android.support.design.widget.TabLayout
android:id="@+id/manhua_viewpager_tablayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@mipmap/titlebar_bg"
app:tabTextColor="#66FFFFFF"
app:tabSelectedTextColor="#66FF0000"
>
    </android.support.design.widget.TabLayout>
<android.support.v4.view.ViewPager
android:id="@+id/manhua_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent">

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

 

然后创建一个ViewPager的FragmentPagerAdapter，在这里面的Fragment 一定要是v4包的，而且要有一个fragment 的列表；

fragments;
    public ComicViewPagerAdapter(FragmentManager fm,ArrayList<Fragment> fragments) {
        super(fm);
        this.fragments=fragments;
    }

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

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

    @Override
    public CharSequence getPageTitle(int position) {
//        return super.getPageTitle(position);
String ret = null;
        switch (position){
            case 0:
                ret="精品";
                break;
            case 1:
                ret="更新";
                break;
            case 2:
                ret="排行";
                break;
            case 3:
                ret="分类";
                break;
        }
        return ret;
    }
}

然后在 Fragment 里面实现ViewPager 和TabLayout 进行联动；注意这里面如果不用ret 去findViewById而是用getActivity的话就会报空指针。

public class ComicFragment extends Fragment {

    private ViewPager mComicViewPager;

    Context context;

    public ComicFragment() {
        // Required empty public constructor
}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View ret =inflater.inflate(R.layout.fragment_comic, container, false);
        // Inflate the layout for this fragment
TabLayout tabLayout = (TabLayout)ret.findViewById(R.id.comic_tablayout);
        mComicViewPager = (ViewPager)ret.findViewById(R.id.comic_viewPager);

        ArrayList<Fragment> fragments = new ArrayList<Fragment>();
        fragments.add(new CategoryFragment());
        fragments.add(new CategoryFragment());
        fragments.add(new CategoryFragment());
        fragments.add(new CategoryFragment());

        ComicViewPagerAdapter adapter = new ComicViewPagerAdapter(getChildFragmentManager(),fragments);

        mComicViewPager.setAdapter(adapter);

        tabLayout.setupWithViewPager(mComicViewPager);

        // 防止ViewPager销毁不在屏幕内部的应用
mComicViewPager.setOffscreenPageLimit(5);

        return ret;

    }

}