如何动态创建Fragment寻呼机适配器

Question

我无法为每个选项卡创建动态布局,我可以通过此构造函数动态创建选项卡(公共MyPagerAdapter(FragmentManager fm,int noOfTabs)),但是不要为每个应创建的每个片段创建每个选项卡的视图. dyanmic.

public class MyPagerAdapter extends FragmentPagerAdapter 
{

        private final String[] TITLES = { "Categories", "Home", "Top Paid", "Top Free", "Top Grossing", "Top New Paid",
                "Top New Free", "Trending" };

        int noOfTabs;

        **public MyPagerAdapter(FragmentManager fm , int noOfTabs) 
        {           
            super(fm);
            this.noOfTabs = noOfTabs;
        }**

        /*public MyPagerAdapter(FragmentManager fm) 
        {
            super(fm);
        }*/

        @Override
        public CharSequence getPageTitle(int position) {
            return TITLES[position];
        }

        @Override
        public int getCount() {
            return noOfTabs; //TITLES.length;
        }

        @Override
        public Fragment getItem(int position) {
            return SuperAwesomeCardFragment.newInstance(position);
        }

    }

我在这里面临的问题应该是动态的而不是静态的三个片段(FragmentA,FragmentB,FragmentC),它可以是任意数量的片段,具体取决于int noOfTabs:

@Override
public Fragment getItem(int position) {
    Fragment fragment =null;
    switch (position) {
        case 0:
            fragment = new FragmentA();
            break;
        case 1:
            fragment = new FragmentB();
            break;              
        case 2:
            fragment = new FragmentC();
            break;          }
    return fragment;    
}

如果有人可以帮助我,请提前感谢,因为我在图书馆PagerSlidingTabStrip的帮助下使用它.

Answer 1

您可以通过在以下位置存储所有片段及其标题的列表来执行此操作PagerAdapter:

/**
 * TabsPagerAdapter.
 *
 * @author Niels
 * @version 1.0
 * @since 11-9-2015
 */
public class TabsPagerAdapter extends FragmentPagerAdapter {

    /**
     * Contains all the fragments.
     */
    private List<Fragment> fragments = new ArrayList<>();

    /**
     * Contains all the tab titles.
     */
    private List<String> tabTitles = new ArrayList<>();

    /**
     * Creates a new PagerAdapter instance.
     *
     * @param fragmentManager The FragmentManager.
     */
    public TabsPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
    }

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

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

    @Override
    public CharSequence getPageTitle(int position) {
        return tabTitles.get(position);
    }

    /**
     * Adds the fragment to the list, also adds the fragment's tab title.
     *
     * @param fragment New instance of the Fragment to be associated with this tab.
     * @param tabTitle A String containing the tab title for this Fragment.
     */
    public void addFragment(Fragment fragment, String tabTitle) {
        fragments.add(fragment);
        tabTitles.add(tabTitle);
    }

}

您可以这样使用:

@Override
public void onCreate() {
    adapter = new TabsPagerAdapter(getSupportFragmentManager()); //TabsPagerAdapter = whatever you named the PagerAdapter
    addFragments();
    viewpager.setAdapter(adapter); //viewpager = ViewPager view instance
    strip.setViewPager(viewpager); //strip = PagerSlidingTabStrip view instance
}

/**
 * Adds fragments to the adapter.
 */
private void addFragments() {
    adapter.addFragment(new Fragment1(), "Fragment1");
    adapter.addFragment(new Fragment2(), "Fragment2");
    adapter.addFragment(new Fragment3(), "Fragment3");
    adapter.addFragment(new Fragment4(), "Fragment4");
}