java - onCreateView() 永远不会在 Fragment 中被调用

Question

我想构建下一个 UI:
TabLayout 带有 2 个选项卡和 2 个不同的 fragment (已解决和未解决)我在 Fragment 中的 onCreateView 从未被调用。

这里我膨胀了我的 viewPager:

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

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

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

    mAdapter = new ViewPagerAdapter(getSupportFragmentManager());
    mAdapter.addFragment(new UnsolvedTasksFragment());
    mAdapter.addFragment(new SolvedTasksFragment());
    viewPager.setAdapter(mAdapter);

    mTabLayout = (TabLayout) findViewById(R.id.tabs);
    mTabLayout.setupWithViewPager(viewPager);

    mTabLayout.getTabAt(0).setText(getString(R.string.tablayout_unsolved));
    mTabLayout.getTabAt(1).setText(getString(R.string.tablayout_solved));

}

我的自定义 ViewPagerAdapter:

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

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

@Override
public Fragment getItem(int position) {
    if (!mFragmentList.isEmpty() && mFragmentList.size() > id)
        return mFragmentList.get(position);
    return new Fragment();
}

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

public void addFragment(Fragment fragment) {
    mFragmentList.add(fragment);
}

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

这是我的 fragment 的示例:

 public class SolvedTasksFragment extends Fragment implements RecyclerViewClickListenerSolved {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
       //Some code here;
        return rootView;
    }

    @Override
    public void itemClick(View v, int position) {
       }
}

也许有人可以看出出了什么问题。
我不需要整个解决方案。

Answer 1

首先设置适配器，然后添加 fragment 。像这样做。更改这些语句

    mAdapter = new ViewPagerAdapter(getSupportFragmentManager());
    mAdapter.addFragment(new UnsolvedTasksFragment());
    mAdapter.addFragment(new SolvedTasksFragment());
    viewPager.setAdapter(mAdapter);

对于这些

mAdapter = new ViewPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
mAdapter.addFragment(new UnsolvedTasksFragment());
mAdapter.addFragment(new SolvedTasksFragment());