可以直接从片段1转到片段3，而片段选项卡无法正常工作

Question

我正在创建像WhatsApp这样的布局，并且使用了ViewPager2。它很完美，但是当我单击特定标签时，它不会去那里。而且，如果我从右到左点击选项卡，它正在移动，但从左到右单击它不会移动。 我尝试了很多解决方案，但似乎没有任何作用。

MainAttivity：

public class MainActivity extends AppCompatActivity {

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

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabLayout);
    tabLayout.addTab(tabLayout.newTab().setText("Camera"));
    tabLayout.addTab(tabLayout.newTab().setText("Chats"));
    tabLayout.addTab(tabLayout.newTab().setText("Status"));
    tabLayout.addTab(tabLayout.newTab().setText("Calls"));
    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

    final ViewPager2 viewPager = (ViewPager2) findViewById(R.id.pager);
    viewPager.setOffscreenPageLimit(3);
    final PagerAdapter adapter = new PagerAdapter(getSupportFragmentManager(), getLifecycle());
    viewPager.setAdapter(adapter);

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

    viewPager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            super.onPageScrolled(position, positionOffset, positionOffsetPixels);
            tabLayout.selectTab(tabLayout.getTabAt(position));
        }
    });
}

}

Pageradapter：

public class PagerAdapter extends FragmentStateAdapter {

public PagerAdapter(@NonNull FragmentManager fragmentManager, @NonNull Lifecycle lifecycle) {
    super(fragmentManager, lifecycle);
}

@NonNull
@Override
public Fragment createFragment(int position) {
    switch(position) {
        case 0:
            CameraFragment cameraFragment = new CameraFragment();
            return cameraFragment;
        case 1:
            ChatsFragment chatsFragment = new ChatsFragment();
            return chatsFragment;
        case 2:
            StatusFragment statusFragment = new StatusFragment();
            return statusFragment;
        case 3:
            CallsFragment callsFragment = new CallsFragment();
            return callsFragment;
        default:
            return new ChatsFragment();
    }
}

@Override
public int getItemCount() {
    return 4;
}

}

Answer 1

使用TableAutMediator ontabselectedListener

进行更改如下

ArrayList<String> title = new ArrayList<>(); // add this before onCreate Method
//---------After onCreate
title.add("Camera");
title.add("Camera");
title.add("Camera");
title.add("Camera"); 

new TabLayoutMediator(tabLayout, viewPager, (tab, position) -> tab.setText(title.get(position))).attach(); //title.get(position) -> here add arraylist of title.

，然后删除下面的这些代码

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

    viewPager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            super.onPageScrolled(position, positionOffset, positionOffsetPixels);
            tabLayout.selectTab(tabLayout.getTabAt(position));
        }
    });