滑动选项卡时更改操作栏标题

Question

所以我在我的项目中设置了一个Tab Acitivty，但事实是我想根据活动的任何一个标签来改变我的ActionBar标题。

我将所有课程都放在单个文件中（默认来自android studio），我已经学习了很多教程和内容，但仍然无法正常工作。

这是我的Tab活动代码

public class TabPages extends AppCompatActivity{


    private SectionsPagerAdapter mSectionsPagerAdapter;


    private ViewPager mViewPager;
    private int[] tabIcons = {
            R.drawable.ic_search_24dp,
            R.drawable.ic_forum_24dp,
    };


    @Override
    public void onBackPressed() {
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_HOME);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
    }

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

       
        mViewPager = (ViewPager) findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(mViewPager);



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        
        getMenuInflater().inflate(R.menu.addbutton,menu);
        getMenuInflater().inflate(R.menu.menu_tab_pages, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        
        int id = item.getItemId();

        if(id==R.id.signOut){
            FirebaseAuth.getInstance().signOut();
            startActivity(new Intent(TabPages.this, MainActivity.class));
        }

        return super.onOptionsItemSelected(item);
    }
    
    public static class PlaceholderFragment extends Fragment {
        
        private static final String ARG_SECTION_NUMBER = "section_number";

        public PlaceholderFragment() {

        }


        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView;
            if(getArguments().getInt(ARG_SECTION_NUMBER)==1){
                return rootView = inflater.inflate(R.layout.fragment_browse_title, container, false);
            } else{
                return rootView = inflater.inflate(R.layout.fragment_chat_history, container, false);
            }


        }
    }


    lic class SectionsPagerAdapter extends FragmentPagerAdapter{

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            
            return PlaceholderFragment.newInstance(position + 1);
        }

        @Override
        public int getCount() {
            // Show 2 total pages.
            return 2;
        }

        @Override
        public CharSequence getPageTitle(int position) {

            return null;
        }

    }
}

感谢帮助

Answer 1

tabLayout.setupWithViewPager(mViewPager);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            mViewPager.setCurrentItem(tab.getPosition());
            //Set title here using setTitle()
        }

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

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

请试一试。