java - TabLayout viewpager开关Tab2仅editext在Tab1上有效

我实现mTabs.addOnTabSelectedListener，并在onTabSelected上检查editext。如果字段不正确，我想保留在Tab1上。
我使用Viewpager，其中使用片段。

你是怎样做的？

主要活动：

public class HomeActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_home_activity);
        TabLayout tabs = findViewById(R.id.tabs);
        ViewPager viewPager = findViewById(R.id.view_pager);
        SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(HomeActivity.this, getSupportFragmentManager(), tabs, viewPager);

        viewPager.setAdapter(sectionsPagerAdapter);

        tabs.setupWithViewPager(viewPager);
    }

}

FragmentAdapter：

public class SectionsPagerAdapter extends FragmentPagerAdapter {

    @StringRes
    private static final int[] TAB_TITLES = new int[] {
        "TAB1",
        "TAB2"
    };
    private final Context mContext;
    private TabLayout mTabs;
    private ViewPager mViewPager;

    public SectionsPagerAdapter(Context context, FragmentManager fm, TabLayout tabs, ViewPager viewPager) {
        super(fm);
        mContext = context;
        mTabs = tabs;
        mViewPager = viewPager;
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        return PlaceholderFragment.newInstance(position + 1, mContext, mTabs, mViewPager);
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return mContext.getResources().getString(TAB_TITLES[position]);
    }

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

谢谢。

最佳答案

片段类：

public class PlaceholderFragment extends Fragment {

private static final String ARG_SECTION_NUMBER = "section_number";
private static int indexTab;
private static Context mContext;
private static TabLayout mTabs;
private static ViewPager mViewPager;

private PageViewModel pageViewModel;

    public static PlaceholderFragment newInstance(int index, Context context, TabLayout tabs, ViewPager viewPager) {
    mContext=context;
    mTabs=tabs;
    mViewPager=viewPager;
    PlaceholderFragment fragment = new PlaceholderFragment();
    Bundle bundle = new Bundle();

    Log.v("index","index:"+index);
    bundle.putInt(ARG_SECTION_NUMBER, index);
    fragment.setArguments(bundle);
    return fragment;
    }

   @Override
   public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.v("onCreate","onCreate");
    pageViewModel = ViewModelProviders.of(this).get(PageViewModel.class);
    int index = 1;
    if (getArguments() != null) {
        index = getArguments().getInt(ARG_SECTION_NUMBER);
        indexTab=index;


    }
    pageViewModel.setIndex(index);



    }

   @Override
   public View onCreateView(
        @NonNull LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    Log.v("onCreateView","onCreateView "+indexTab);
    View root;
    if(indexTab==2){
        indexTab=1; //FORCE
        root = inflater.inflate(R.layout.fragment_one, container, false);


         mTabs.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener()          {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {

          }

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

            }

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

            }
        });


      }else{

        root = inflater.inflate(R.layout.fragment_two, container, false);


       }

      return root;

     }
    }