Question

我有一个包含3个标签片段的viewPager。第一个和第二个片段工作正常但是当我扫到第三个标签时我没有看到他。第三个选项卡仅在viewPager的活动重新加载时移动（移动到另一个活动并返回）。

我的代码：

    private void setupViewPager(ViewPager viewPager) {
    adapter = new PagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new Fragment1(), Constants.TAB_0);
    adapter.addFragment(new Fragment2(), Constants.TAB_1);
    adapter.addFragment(new Fragment3(), Constants.TAB_2);

    viewPager.setAdapter(adapter);

    viewPager.setOffscreenPageLimit(3);
}

寻呼机适配器：

public class PagerAdapter extends FragmentPagerAdapter {
/*
 * Arraylist used to contain the fragments
 * and contain fragments title's
 */
private final List<Fragment> fragmentList = new ArrayList<>();
private final List<String> fragmentTitleList = new ArrayList<>();

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

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

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

//Adds the fragment and it's title. Called in MainActivity
public void addFragment(Fragment fragment, String title) {
    fragmentList.add(fragment);
    fragmentTitleList.add(title);
}

//Retrieves the title of the tab
@Override
public CharSequence getPageTitle(int position) {
    return fragmentTitleList.get(position);
}

@Override
public int getItemPosition(Object object) {
    return POSITION_NONE;
}

}

Answer 1

这是我的适配器，在getItem上我将片段对象设置为Fragment活动。

public class SectionPagerAdapter extends FragmentPagerAdapter {

    Fragment fragment;

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


    @Override
    public Fragment getItem(int position) {

        if (position == 0){
            fragment = new FragmentOne();
        }

        else if (position == 1){
            fragment = new FragmentTwo();
        }

        else if (position == 2){
            fragment = new FragmentThree();
        }

        return fragment;
    }

    @Override
    public int getCount() {
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
            case 0:
                return "name one";
            case 1:
                return "name two";
            case 2:
                return "name three";
        }
        return null;

    }

}

然后在我的主要活动中，我称之为：

ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
SectionPagerAdapter sectionPagerAdapter = new SectionPagerAdapter(getSupportFragmentManager());
mViewPager.setAdapter(sectionPagerAdapter);


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

尝试用上面的代码替换代码，让我知道它是否有帮助！

Answer 2

USE new PagerAdapter(getChildSupportFragmentManager()); 而不是 getSupportFragmentManager()

试试这个!!

Android - ViewPager第三个标签未显示

2 个答案: