[移动开发]android 嵌套ViewPager + Fragment实现仿头条UI框架Demo

1. 实现效果

2. 核心实现

? 1)BaseViewPagerAdapter.java

public class BaseViewPagerAdapter extends FragmentPagerAdapter {
    protected ViewPager mViewPager;
    protected LinearLayout mTabContainer;
    protected int[] mTabResArray;
    protected List<Fragment> mFragmentList= new ArrayList<>();
    protected List<View> mTabViews = new ArrayList<>();

    public BaseViewPagerAdapter(FragmentManager fragmentManager, ViewPager viewPager, LinearLayout tabContainer, int[] tabResArray) {
        super(fragmentManager);
        this.mViewPager = viewPager;
        this.mTabContainer = tabContainer;
        this.mTabResArray = tabResArray;
        this.mViewPager.setAdapter(this);
        this.mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                updateTabViewUI(position);
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

    protected void initTabView(int pos) {
        View singleTabView = LayoutInflater.from(mTabContainer.getContext()).inflate(mTabResArray[pos], mTabContainer, false);
        LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams)singleTabView.getLayoutParams();
        layoutParams.width = 0;
        layoutParams.height = DisplayUtil.dp2px(mTabContainer.getContext(), getTabViewHeightDp());
        layoutParams.weight = 1;
        mTabContainer.addView(singleTabView, layoutParams);
        GestureDetector gestureDetector = new GestureDetector(singleTabView.getContext(), new GestureDetector.OnGestureListener() {
            @Override
            public boolean onDown(MotionEvent e) {
                return true;
            }

            @Override
            public void onShowPress(MotionEvent e) {

            }

            @Override
            public boolean onSingleTapUp(MotionEvent e) {
                changeTabView(pos);
                return true;
            }

            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
                return false;
            }

            @Override
            public void onLongPress(MotionEvent e) {

            }

            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                return false;
            }
        });
        singleTabView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return gestureDetector.onTouchEvent(event);
            }
        });
        mTabViews.add(singleTabView);
    }

    protected int getTabViewHeightDp() {
        return 50;
    }

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

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

    /**
     * 外部set fragment list
     * @param fragmentList
     */
    public void setFragmentList(List<Fragment> fragmentList) {
        this.mFragmentList.clear();
        this.mFragmentList.addAll(fragmentList);
        mViewPager.setOffscreenPageLimit(mFragmentList.size());
        mTabContainer.removeAllViews();
        this.mTabViews.clear();
        //初始化tab view
        for(int pos = 0; pos < mTabResArray.length; pos++) {
            initTabView(pos);
        }
        //更新tab view ui
        updateTabViewUI(0);
        //记得notify data
        notifyDataSetChanged();
    }

    /**
     * 切换tab
     * @param pos
     */
    protected void changeTabView(int pos) {
        mViewPager.setCurrentItem(pos);
    }


    /**
     * 更新tab ui
     * @param position
     */
    public void updateTabViewUI(int position) {
        for(int i =0; i < mTabViews.size(); i++) {
            View tabView = mTabViews.get(i);
            TextView tabTitleView = tabView.findViewById(R.id.tab_title);
            if(i == position) {
                tabTitleView.setTextColor(tabTitleView.getResources().getColor(R.color.white));
            } else {
                tabTitleView.setTextColor(tabTitleView.getResources().getColor(R.color.medium_orange));
            }
        }
    }
}

? ?MainViewPagerAdapter.java?

public class MainViewPagerAdapter extends BaseViewPagerAdapter {
    public MainViewPagerAdapter(FragmentManager fragmentManager, ViewPager viewPager, LinearLayout tabContainer, int[] tabResArray) {
        super(fragmentManager, viewPager, tabContainer, tabResArray);
    }


}

? ? TabSubViewPagerAdapter.java

public class TabSubViewPagerAdapter extends BaseViewPagerAdapter {
    public TabSubViewPagerAdapter(FragmentManager fragmentManager, ViewPager viewPager, LinearLayout tabContainer, int[] tabResArray) {
        super(fragmentManager, viewPager, tabContainer, tabResArray);
    }


    @Override
    protected int getTabViewHeightDp() {
        return 30;
    }

    /**
     * 更新tab ui
     * @param position
     */
    @Override
    public void updateTabViewUI(int position) {
        for(int i =0; i < mTabViews.size(); i++) {
            View tabView = mTabViews.get(i);
            TextView tabTitleView = tabView.findViewById(R.id.tab_title);
            if(i == position) {
                tabTitleView.setTextColor(tabTitleView.getResources().getColor(R.color.white));
            } else {
                tabTitleView.setTextColor(tabTitleView.getResources().getColor(R.color.medium_green));
            }
        }
    }
}

? 2) MainActivity.java

public class MainActivity extends AppCompatActivity {

    private MainViewPagerAdapter mMainViewPagerAdapter;
    private ViewPager mViewPager;
    private LinearLayout mTabContainerLy;



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

    private void initUI() {
        mViewPager = findViewById(R.id.view_pager);
        mTabContainerLy = findViewById(R.id.tab_container_ly);
        //adapter填充数据
        List<Fragment> fragments = new ArrayList<>();
        fragments.add(MainFragment.build());
        fragments.add(MediaFragment.build());
        fragments.add(JetPackFragment.build());
        int[] tabResArray = new int[]{R.layout.fragment_tab_main, R.layout.fragment_tab_media, R.layout.fragment_tab_jetpack};
        mMainViewPagerAdapter = new MainViewPagerAdapter(getSupportFragmentManager(), mViewPager, mTabContainerLy, tabResArray);
        mMainViewPagerAdapter.setFragmentList(fragments);
    }
}

? ?3）MainFragment.java

public class MainFragment extends Fragment {

    private TabSubViewPagerAdapter mTabSubViewPagerAdapter;
    private ViewPager mViewPager;
    private LinearLayout mTabContainerLy;


    public static MainFragment build() {
        return new MainFragment();
    }

    @Override
    public View onCreateView(@NonNull @NotNull LayoutInflater inflater, @Nullable @org.jetbrains.annotations.Nullable ViewGroup container, @Nullable @org.jetbrains.annotations.Nullable Bundle savedInstanceState) {
        View rootView = LayoutInflater.from(getActivity()).inflate(R.layout.fragment_main, null, true);
        mViewPager = rootView.findViewById(R.id.view_pager);
        mTabContainerLy = rootView.findViewById(R.id.tab_container_ly);
        //adapter填充数据
        List<Fragment> fragments = new ArrayList<>();
        fragments.add(SubTabFragment1.build());
        fragments.add(SubTabFragment2.build());
        fragments.add(SubTabFragment3.build());
        int[] tabResArray = new int[]{R.layout.fragment_sub_tab_title1, R.layout.fragment_sub_tab_title2, R.layout.fragment_sub_tab_title3};
        mTabSubViewPagerAdapter = new TabSubViewPagerAdapter(getChildFragmentManager(), mViewPager, mTabContainerLy, tabResArray);
        mTabSubViewPagerAdapter.setFragmentList(fragments);
        return rootView;
    }
}

3. 地址:

https://mikel.coding.net/p/androiddemo/d/MikelProjectDemo/git???????