Question

我在我的活动中设置了一个标签滑块，根据所选的片段调用3个独立的片段。问题是当选择第一个选项卡时，会显示“Science” - 它是在第一个片段的onCreateView（）方法上设置的。但是，在没有单击其他选项卡的情况下，将显示“技术”和“运动”。

据我所知，我最后两个实现它的方式只应在选择相应的选项卡后显示。

这是我的页面适配器类

public class PagerAdapter extends FragmentPagerAdapter {
    final int PAGE_COUNT = 3; //Represents the number of tabs
    private String tabTitles[] = new String[]{"Technology", "Science", "Sports"}; //Tab values defined in an array
    private Context context;

    public PagerAdapter(FragmentManager fm, Context context)
    {
        super(fm);
        this.context = context;
    }

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

    //determines the fragment depending on the selected tab
    @Override
    public Fragment getItem(int position)
    {
        if(position==0)
            return TechnologyFragment.newInstance(position+1);
        else if(position==1)
            return ScienceFragment.newInstance(position+1);
        else if(position==2)
            return SportsFragment.newInstance(position+1);
        else
            return null;
    }

    //displays the title for each tab
    @Override
    public CharSequence getPageTitle(int position)
    {
        // Generate title based on item position
        return tabTitles[position];
    }
}

这是新闻类 - 设置了视图寻呼机和标签布局

public class News extends AppCompatActivity {
    //Here the viewPager is connected to the PagerAdapter class
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_news);

        //This component will be used to page between the various fragments created.
        final ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
        viewPager.setAdapter(new PagerAdapter(getSupportFragmentManager(), News.this));

        //the tabLayout is given the viewPager to connect to the pager with the tabs
        TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
        tabLayout.setupWithViewPager(viewPager);
        //the following was used so the tabs fill up the width of the screen being responsive for all devices and orientations
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
        tabLayout.setTabMode(TabLayout.MODE_FIXED);

    }

}

这些是片段类 - （其他两个是相同的，但使用Toast表示不同的消息）

public class ScienceFragment extends Fragment {

    //other methods

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.activity_science_fragment, container, false);
        toShow=getAll();
        GridView gridView = (GridView)view.findViewById(R.id.gridview);
        gridView.setAdapter(new ImageAdapter(getContext(),toShow));
        Toast.makeText(getContext(), "Science", Toast.LENGTH_SHORT).show();
        return view;
    }
}

感谢任何帮助

Tab Slider Android Studio无法正常工作

0 个答案: