整理自：
http://www.cnblogs.com/JohnTsai/p/4715454.html

直接切入正題，如果我們要實(shí)現(xiàn)下面這兩種效果該怎么做呢？

1

2

第一種效果還算比較簡(jiǎn)單拆讯，使用ViewPager再加上FragmentPagerAdapter就可以實(shí)現(xiàn)驯耻，其中，這其中最麻煩的就是tab下面那個(gè)導(dǎo)航條融击，需要根據(jù)屏幕大小以及標(biāo)簽個(gè)數(shù)來動(dòng)態(tài)設(shè)置其位置
而第二種效果除了導(dǎo)航條的位置的變換筑公，其長(zhǎng)度以及tab的位置都需要仔細(xì)地去考慮···真的是非常麻煩

之前一直想著自己能不能對(duì)這種效果進(jìn)行封裝，但是現(xiàn)在谷歌自己以及發(fā)布了一個(gè)庫-TabLayout尊浪，可以直接實(shí)現(xiàn)這樣的效果啦匣屡。這個(gè)TabLayout的具體知識(shí)就不在這說了，網(wǎng)上有很多資料拇涤。

最后附上如果是自己實(shí)現(xiàn)第一種那樣的效果怎么做：
因?yàn)樽约簩?shí)現(xiàn)不是我們這里的重點(diǎn)捣作，所以我就直接將代碼發(fā)上來就不解釋了

public class MySongFrag extends Fragment {
    @BindView(R.id.view_pager)
    ViewPager viewPager;
    @BindView(R.id.tv_album)
    TextView tvAlbum;
    @BindView(R.id.tv_singer)
    TextView tvSinger;
    @BindView(R.id.tv_song)
    TextView tvSong;
    @BindView(R.id.iv_tab_line)
    ImageView ivTabLine;
    @BindView(R.id.layout_tab)
    LinearLayout tabLayout;

    ResourceUtils resourceUtils;


    FragmentPagerAdapter fragmentPagerAdapter;
    List<Fragment> fragmentList=new ArrayList<Fragment>();

    //當(dāng)前顯示頁面的下標(biāo)
    double currentIndex;
    //屏幕寬度
    double screenWidth;
    //上面的那個(gè)tab的寬度，是屏幕寬度的六分之四
    double tabWidth;
    //屏幕寬度的六分之一
    double sixInOne;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view=inflater.inflate(R.layout.frag_my_song,null);
        ButterKnife.bind(this,view);

        init();
        initTabWidth();
        initViewPager();

        return view;
    }

    private void init() {
        resourceUtils=new ResourceUtils(getActivity());
    }

    //設(shè)置上面tab寬度為屏幕寬度三分之二
    private void initTabWidth() {
        screenWidth=getActivity().getWindowManager().getDefaultDisplay().getWidth();
        tabWidth=screenWidth*2/3;
        sixInOne=screenWidth/6;

        LinearLayout.LayoutParams lp= (LinearLayout.LayoutParams) tabLayout.getLayoutParams();
        lp.width= (int) tabWidth;
        tabLayout.setLayoutParams(lp);

        LinearLayout.LayoutParams lpIv= (LinearLayout.LayoutParams) ivTabLine.getLayoutParams();
        lpIv.width=(int) tabWidth/3;
        lpIv.leftMargin=(int) sixInOne;
        ivTabLine.setLayoutParams(lpIv);
    }

    private void initViewPager() {
        SongFrag songFrag=new SongFrag();
        SingerFrag singerFrag=new SingerFrag();
        AlbumFrag albumFrag=new AlbumFrag();

        fragmentList.add(songFrag);
        fragmentList.add(singerFrag);
        fragmentList.add(albumFrag);

        fragmentPagerAdapter=new FragmentPagerAdapter(getFragmentManager()) {
            @Override
            public Fragment getItem(int position) {
                return fragmentList.get(position);
            }

            @Override
            public int getCount() {
                return fragmentList.size();
            }
        };
        viewPager.setAdapter(fragmentPagerAdapter);
        viewPager.setCurrentItem(0);
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) ivTabLine
                        .getLayoutParams();


                /**
        
                 * 利用currentIndex(當(dāng)前所在頁面)和position(下一個(gè)頁面)以及offset來
                 * 設(shè)置mTabLineIv的左邊距 滑動(dòng)場(chǎng)景：
                 * 記3個(gè)頁面,
                 * 從左到右分別為0,1,2
                 * 0->1; 1->2; 2->1; 1->0
                 */
                if (currentIndex == 0 && position == 0)// 0->1
                {
                    lp.leftMargin = (int) (sixInOne+positionOffset * (tabWidth * 1.0 / 3) + currentIndex
                            * (tabWidth / 3));
                } else if (currentIndex == 1 && position == 0) // 1->0
                {
                    lp.leftMargin = (int) (-(1 - positionOffset)
                            * (tabWidth * 1.0 / 3)+sixInOne + currentIndex
                            * (tabWidth / 3));

                } else if (currentIndex == 1 && position == 1) // 1->2
                {
                    lp.leftMargin = (int) (positionOffset * (tabWidth * 1.0 / 3) + sixInOne+currentIndex
                            * (tabWidth / 3));

                } else if (currentIndex == 2 && position == 1) // 2->1
                {
                    lp.leftMargin = (int) (-(1 - positionOffset)
                            * (tabWidth * 1.0 / 3) +sixInOne+ currentIndex
                            * (tabWidth / 3));
                }
                ivTabLine.setLayoutParams(lp);
            }

            @Override
            public void onPageSelected(int position) {
                resetTextView();
                switch (position) {
                    case 0:
                        tvSong.setTextColor(resourceUtils.getColorIntRes(R.color.myColorAccent));
                        break;
                    case 1:
                        tvSinger.setTextColor(resourceUtils.getColorIntRes(R.color.myColorAccent));
                        break;
                    case 2:
                        tvAlbum.setTextColor(resourceUtils.getColorIntRes(R.color.myColorAccent));
                        break;
                }
                currentIndex = position;
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

    }

    private void resetTextView() {
        tvAlbum.setTextColor(resourceUtils.getColorIntRes(R.color.tab_text_unchecked));
        tvSinger.setTextColor(resourceUtils.getColorIntRes(R.color.tab_text_unchecked));
        tvSong.setTextColor(resourceUtils.getColorIntRes(R.color.tab_text_unchecked));

    }
}