android - 删除页面并将其添加到 FragmentPagerAdapter

Question

我正在使用带有 5 页的 fragment 寻呼机适配器。并且我将适配器设置为如下所示查看寻呼机

 public class xxx extends FragmentPagerAdapter
    {
        final int PAGE_COUNT_LOGGED_IN = 6;
        final int PAGE_COUNT_LOGGED_OUT = 2;
        TextView oTextView = null;
        LayoutInflater inflater = null;
        PagerTabStrip m_oPageTabStrip = null;
        String m_strTab = null;
        String[] m_strArray = null;     
        Context m_oContext = null;

        /** Constructor of the class */
        public xxxx (Context context, android.support.v4.app.FragmentManager oFragmentManager) 
        {
            super (oFragmentManager);
            m_oContext = context;
        }

        /** This method will be invoked when a page is requested to create */
        @Override
        public Fragment getItem(int arg0) 
        {       
            xxxxFragment myFragment = new xxxFragment ();
            Bundle data = new Bundle();
            data.putInt("current_page", arg0+1);
            myFragment.setArguments(data);
            return myFragment;
        }

        /** Returns the number of pages */
        @Override
        public int getCount() 
        {       
            if (Utility.m_bIsLoggedIn == true)
            {
                return PAGE_COUNT_LOGGED_IN;
            }
            else
            {
                return PAGE_COUNT_LOGGED_OUT;
            }
        }

        @Override
        public CharSequence getPageTitle(int position) 
        {
            String strText = " ";

            switch(position)
            {
            case 0:
                strText = getBaseContext().getString(R.string.ccc);
                break;
            case 1:
                strText = getBaseContext().getString(R.string.bbb);
                break;
            case 2:
                strText = getBaseContext().getString(R.string.bbb);
                break;
            case 3:
                strText = getBaseContext().getString(R.string.bbb);
                break;
            case 4:
                strText = getBaseContext().getString(R.string.bbb);
                break;
            case 5:
                strText = getBaseContext().getString(R.string.Sbbb);
                break;
            }

        }

在 fragment 中，我为每个页面分别创建了一个线性布局，如下所示

bbb.m_oSharedPage = (LinearLayout) LayoutInflater.from(Utility.m_oService).inflate(R.layout.viewpage, null);
                            iView = Utility._YOURS_SHARED;
                            oCurrentPage = .m_oSharedPage;

我按如下方式设置适配器

m_oPager.setAdapter(m_oPagerAdapter);

我的问题是如何动态添加和删除第 5 页...比如在某些情况下我需要第 5 页，而在某些情况下我需要删除第 5 页。

Answer 1

我有一些可能有用的东西，我不会更改 Fragment，只是将其删除并重新添加。这只会从最后一个位置开始改变。换句话说，如果您有五个 Fragments 并且想要删除第三个​​，那么这将不起作用。我不确定这是最好的解决方案，但这是我所做的:

mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

然后，作为示例，我使用添加和删除 click 方法:

public void remove(View v) {
    // Change the count to whatever you would like
    mSectionsPagerAdapter.setCount(1);
    // Triggers a redraw of the PageAdapter
    mSectionsPagerAdapter.notifyDataSetChanged();
}

public void add(View v) {
    // Change the count back to the initial count
    mSectionsPagerAdapter.setCount(2);
    // Triggers a redraw of the PageAdapter
    mSectionsPagerAdapter.notifyDataSetChanged();
}

我向我的 SectionsPagerAdapter 添加了一个 setCount() 方法:

public void setCount(int count) {
    this._count = count;
}

将 getCount() 更改为并添加了默认计数:

private int _count = 2;

@Override
public int getCount() {
    return this._count;
}

这是我的完整SectionsPagerAdapter:

public class SectionsPagerAdapter extends FragmentPagerAdapter {
    private int _count = 2;

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        return super.instantiateItem(container, position);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position) {
        case 0:
            return new FragmentOne();
        case 1:
            return new FragmentTwo();
        default:
            return null;
        }
    }

    public void setCount(int count) {
        this._count = count;
    }

    @Override
    public int getCount() {
        return this._count;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
        case 0:
            return getString(R.string.fragment_title_one).toUpperCase(Locale.ENGLISH);
        case 1:
            return getString(R.string.fragment_title_two).toUpperCase(Locale.ENGLISH);
        }
        return null;
    }
}