Android TabLayout 怎么实现底部Tab

public class CustomBotTabItem {

  private TabLayout mTabLayout;
  private ViewPager mViewPager;
  private Context mContext;
  //底部Tab标题
  private final String[] mTitles = {"主页", "理财", "添加", "消息", "我的"};
  //返回CustomBotTabItem实例
  public static CustomBotTabItem create() {
    return TabItemHolder.sCustomTabItem;
  }
  //创建CustomBotTabItem实例
  private static class TabItemHolder {
    private static CustomBotTabItem sCustomTabItem = new CustomBotTabItem();
  }
  //引入布局需要的Context
  public CustomBotTabItem setContext(Context context) {
    mContext = context;
    return this;
  }
  //需要自定义的TabLayout
  public CustomBotTabItem setTabLayout(TabLayout tabLayout) {
    mTabLayout = tabLayout;
    return this;
  }
  //设置与TabLayout关联的ViewPager
  public CustomBotTabItem setViewPager(ViewPager viewPager) {
    mViewPager = viewPager;
    return this;
  }
  //创建Tab
  public CustomBotTabItem build() {
    initTabLayout();
    return this;
  }
  //初始化Tab
  private void initTabLayout() {
    mTabLayout.setupWithViewPager(mViewPager);
    //第二个参数为selector，下同
    mTabLayout.getTabAt(0).setCustomView(getTabView(0, R.drawable.home_icon_selector));
    mTabLayout.getTabAt(1).setCustomView(getTabView(1, R.drawable.manage_icon_selector));
    mTabLayout.getTabAt(2).setCustomView(getTabView(2, R.drawable.add_icon_selector));
    mTabLayout.getTabAt(3).setCustomView(getTabView(3, R.drawable.find_icon_selector));
    mTabLayout.getTabAt(4).setCustomView(getTabView(4, R.drawable.money_icon_selector));
    tabSelectListener();
  }
   //自定义Tab样式
  private View getTabView(final int position, int resId) {
    final View view = LayoutInflater.from(mContext).inflate(R.layout.bottom_tab_item, null);
    TextView tvTitle = (TextView) view.findViewById(R.id.id_tv_title);
    final ImageView ivTitle = (ImageView) view.findViewById(R.id.id_iv_title);
    ivTitle.setImageResource(resId);
    tvTitle.setText(mTitles[position]);
    //默认第一个tab选中，设置字体为选中色
    if (position == 0) {
      tvTitle.setTextColor(Color.parseColor("#4192e3"));
    } else {
      tvTitle.setTextColor(Color.parseColor("#262a3b"));
    }
    //点击Tab切换
    view.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        mViewPager.setCurrentItem(position);
      }
    });
    return view;
  }
  //Tab监听
  private void tabSelectListener() {
    mTabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
      @Override
      public void onTabSelected(TabLayout.Tab tab) {
        changeTabStatus(tab, true);
      }

      @Override
      public void onTabUnselected(TabLayout.Tab tab) {
        changeTabStatus(tab, false);
      }

      @Override
      public void onTabReselected(TabLayout.Tab tab) {

      }
    });
  }
  //切换Tab文字是否选中的的颜色
  private void changeTabStatus(TabLayout.Tab tab, boolean selected) {
    View view = tab.getCustomView();
    if (view == null) {
      return;
    }
    TextView tvTitle = (TextView) view.findViewById(R.id.id_tv_title);
    if (selected) {
      tvTitle.setTextColor(Color.parseColor("#4192e3"));
    } else {
      tvTitle.setTextColor(Color.parseColor("#262a3b"));
    }
  }
}

public class BottomTabLayoutActivity extends AppCompatActivity {
  private TabLayout mTabLayout;
  private ViewPager mViewPager;
  private List mFragmentList;

  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_bot_tab_layout);
    findView();
    initFragmentList();
    setVpAdapter();
    CustomBotTabItem item = CustomBotTabItem.create();
    item.setContext(this)
        .setViewPager(mViewPager)
        .setTabLayout(mTabLayout)
        .build();
  }
  //findViewById
  private void findView() {
    mTabLayout = (TabLayout) findViewById(R.id.id_tab_layout);
    mViewPager = (ViewPager) findViewById(R.id.id_vp);
  }
  //初始化需要的Fragment
  private void initFragmentList() {
    mFragmentList = new ArrayList<>();
    mFragmentList.add(TabFragment.getInstance("主页"));
    mFragmentList.add(TabFragment.getInstance("理财"));
    mFragmentList.add(TabFragment.getInstance("添加"));
    mFragmentList.add(TabFragment.getInstance("消息"));
    mFragmentList.add(TabFragment.getInstance("我的"));
  }
  //设置ViewPager的Adapter
  private void setVpAdapter() {
    mViewPager.setAdapter(new FragmentAdapter(getSupportFragmentManager(), mFragmentList, this));
  }
}