摘要：一簡介使用起來就是我們通過創建給它填充多個，左右滑動時，切換不同的。

Viewpager使用起來就是我們通過創建adapter給它填充多個view，左右滑動時，切換不同的view。Google官方是建議我們使用Fragment來填充ViewPager的，這樣 可以更加方便的生成每個Page，以及管理每個Page的生命周期

implementation "com.android.support:design:28.0.0"

xml

activity中通過id來尋找控件

 viewPager = findViewById(R.id.viewPager);
 tabLayout = findViewById(R.id.tabLayout);

創建ViewPager適配器

 public class PageAdapter extends FragmentPagerAdapter {

   List fragmentList = new ArrayList<>();
   List titleList = new ArrayList<>();

   public PageAdapter(FragmentManager fm,List fragmentList,List titleList) {
       super(fm);
       this.fragmentList = fragmentList;
       this.titleList = titleList;
   }

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

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

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

準備相關數據（fragment，title）

 private List getTitleList() {
       titleList.add("Tab1");
       titleList.add("Tab2");
       return titleList;
   }
 private List getFragmentList() {

       pageModels.add(new PageModel(R.layout.examplelayout1));
       pageModels.add(new PageModel(R.layout.examplelayout2));

       for (int i = 0; i < pageModels.size(); i++) {
           pageFragment = PageFragment.newInstance(pageModels.get(i).exampleLayoutRes);
           fragmentList.add(pageFragment);
       }
       return fragmentList;
   }

   class PageModel {
       @LayoutRes
       int exampleLayoutRes;

       public PageModel(@LayoutRes int exampleLayoutRes) {
           this.exampleLayoutRes = exampleLayoutRes;
       }
   }

設置viewPager適配器

 viewPager.setAdapter(new PageAdapter(getSupportFragmentManager(), getFragmentList(), getTitleList()));

設置tab標題

如果不設置此項，tab將無法顯示

 tabLayout.setupWithViewPager(viewPager);
 

布局相關：

activity_main

fragment_page

examplelayout1

examplelayout2

功能代碼

MainActivity

public class MainActivity extends AppCompatActivity {
    ViewPager viewPager;
    TabLayout tabLayout;
    List titleList = new ArrayList<>();
    List fragmentList = new ArrayList<>();
    List pageModels = new ArrayList<>();
    PageFragment pageFragment;

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

        doBisness();
    }

    private void doBisness() {
        viewPager = findViewById(R.id.viewPager);
        tabLayout = findViewById(R.id.tabLayout);
        viewPager.setAdapter(new PageAdapter(getSupportFragmentManager(), getFragmentList(), getTitleList()));

        tabLayout.setupWithViewPager(viewPager);
    }

    private List getTitleList() {
        titleList.add("Tab1");
        titleList.add("Tab2");
        return titleList;
    }

    private List getFragmentList() {

        pageModels.add(new PageModel(R.layout.examplelayout1));
        pageModels.add(new PageModel(R.layout.examplelayout2));

        for (int i = 0; i < pageModels.size(); i++) {
            pageFragment = PageFragment.newInstance(pageModels.get(i).exampleLayoutRes);
            fragmentList.add(pageFragment);
        }
        return fragmentList;
    }

    class PageModel {
        @LayoutRes
        int exampleLayoutRes;

        public PageModel(@LayoutRes int exampleLayoutRes) {
            this.exampleLayoutRes = exampleLayoutRes;
        }
    }
}

PageFragment

public class PageFragment extends Fragment {

    @LayoutRes
    int exampleLayoutRes;

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     */
    public static PageFragment newInstance(@LayoutRes int exampleLayoutRes) {
        PageFragment fragment = new PageFragment();
        Bundle args = new Bundle();
        args.putInt("exampleLayoutRes", exampleLayoutRes);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            exampleLayoutRes = getArguments().getInt("exampleLayoutRes");
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_page, container, false);
        ViewStub exampleStub = view.findViewById(R.id.exampleViewStub);
        exampleStub.setLayoutResource(exampleLayoutRes);
        exampleStub.inflate();
        return view;
    }

}

PageAdapter

public class PageAdapter extends FragmentPagerAdapter {

    List fragmentList = new ArrayList<>();
    List titleList = new ArrayList<>();

    public PageAdapter(FragmentManager fm,List fragmentList,List titleList) {
        super(fm);
        this.fragmentList = fragmentList;
        this.titleList = titleList;
    }

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

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

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

https://github.com/fr1014/vie...