单击事件不是working.How，我可以删除箭头涂上的应用程序名吗？而且，滑动选项卡正在工作，但是当我单击任何选项卡(tab1/tab2/tab3 3)时，为什么呢？

Question

如何删除应用程序名旁边的箭头？此外，我的滑动选项卡正在工作，但当我单击任何选项卡(tab1/tab2/tab3 3)时，单击事件就无法工作。为什么？

public class MainActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private TabLayout tabLayout;
    private ViewPager viewPager;
    private int[] tabIcons = {R.drawable.ic_action_home,
            R.drawable.ic_action_categories,
            R.drawable.ic_action_notification,
            R.drawable.ic_action_profile};


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

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setTitle(R.string.my_tab_title);
        getSupportActionBar().setIcon(R.mipmap.ic_launcher);


        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        viewPager = (ViewPager) findViewById(R.id.Viewpager);
        setupViewPager(viewPager);


        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);
        setupTabIcons();
    }
    private void setupTabIcons() {
        tabLayout.getTabAt(0).setIcon(tabIcons[0]);
        tabLayout.getTabAt(1).setIcon(tabIcons[1]);
        tabLayout.getTabAt(2).setIcon(tabIcons[2]);
        tabLayout.getTabAt(3).setIcon(tabIcons[3]);
    }

    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFragment(new OneFragment(), "ONE");
        adapter.addFragment(new TwoFragment(), "TWO");
        adapter.addFragment(new ThreeFragment(), "THREE");
        adapter.addFragment(new FourFragment(), "FOUR");
        viewPager.setAdapter(adapter);
    }

    class ViewPagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();


        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

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

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

        public void addFragment(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return null;
        }

    }
}

Answer 1

要删除导航按钮，只需删除行：

getSupportActionBar().setDisplayHomeAsUpEnabled(true)；

Answer 2

当选项卡被选中时，您必须添加此代码以启用更改：

tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

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

        }
    });

另外，正如上面其他人所建议的，只要删除下面的一行就可以隐藏回箭头：

getSupportActionBar().setDisplayHomeAsUpEnabled(true);

这就是我认为你上面的代码中缺少的东西；祝你好运！