android - FragmentPagerAdapter 中的 fragment

Question

我想要一个类中有 4 个可滚动选项卡的选项卡。我实现了以下示例并且它有效:

mAdapter = new MyAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mAdapter);

...

public static class MyAdapter extends FragmentPagerAdapter {
    public MyAdapter(FragmentManager fm) {
        super(fm);
    }
    @Override
    public int getCount() {
        return NUM_ITEMS;  //NUM_ITEMS=4
    }
    @Override
    public ArrayListFragment getItem(int position) {
        return ArrayListFragment.newInstance(position);
    }
    @Override
    public CharSequence getPageTitle(int position) {
        switch(position) {
        case 0:
            return "TAB1";
        case 1:
            return "TAB2";
        case 2:
            return "TAB3";
        case 3:
            return "TAB4";
        default:
            return "ERROR";
        }       
    }
}

...

    public static class ArrayListFragment extends ListFragment {
    int mNum;

    static ArrayListFragment newInstance(int num) {
        ArrayListFragment f = new ArrayListFragment();

        Bundle args = new Bundle();
        args.putInt("num", num);
        f.setArguments(args);

        return f;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mNum = getArguments() != null ? getArguments().getInt("num") : 1;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        switch(mNum) {
        case 0:
            View v0 = inflater.inflate(R.layout.fragment_pager_list, container, false);
            return v0;
        case 1:
            View v1 = inflater.inflate(R.layout.fragment_pager_list, container, false);
            return v1;
        case 2:
            View v2 = inflater.inflate(R.layout.fragment_pager_list, container, false);
            return v2;
        case 3:
            View v3 = inflater.inflate(R.layout.fragment_pager_list, container, false);
            return v3;
        default:
            View vd = inflater.inflate(R.layout.fragment_pager_list, container, false);
            return vd;              
        }
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, Titles)); 
    }
    //Titles={"TAB1", "TAB2", "TAB3", "TAB4"}
    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        Log.i("FragmentList", "Item clicked: " + id);
    }


}

我在每个 View 中放置的 fragment_pager_list 布局如下:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:drawable/gallery_thumb">

<TextView android:id="@+id/text"
    android:layout_width="match_parent" android:layout_height="wrap_content"
    android:gravity="center_vertical|center_horizontal"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="HELLO WORLD"/>

<!-- The frame layout is here since we will be showing either
the empty view or the list view.  -->
<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="0dip"
    android:layout_weight="1" >
    <!-- Here is the list. Since we are using a ListActivity, we
         have to call it "@android:id/list" so ListActivity will
         find it -->
    <ListView android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:drawSelectorOnTop="false"/>

    <!-- Here is the view to show if the list is emtpy -->
    <TextView android:id="@android:id/empty"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="No items."/>

</FrameLayout>

问题是我想在每个选项卡的每个 View 中放置不同的布局。我尝试修改代码，使“ArrayListFragment”继承自“Fragment”而不是“ListFragment”，以加载不包含“ListView”但包含“RelativeLayout”或“LinearLayout”的布局，但无法使其正常工作。

拜托，如果有人能帮助我，我需要在选项卡上加载不同的 View ，并且它们包含除 ListView 之外的其他元素。

非常感谢。

Answer 1

你最好为不同的布局制作每个 fragment 。您可以将 addFragment(Fragment fragment) 方法添加到 MyAdapter。

mAdapter = new MyAdapter(getSupportFragmentManager());
for(int i=0; i<4; i++) {
    Fragment fragment = null;
    switch(i) {
    case 0: 
        fragment = FirstFragment.newInstance();
        break;
    case 1:
        fragment = SecondFragment.newInstance();
        break;
    case 2:
        fragment = ThirdFragment.newInstance();
        break;
    case 3:
        fragment = FourthFragment.newInstance();
        break;
    }
    mAdapter.addFragment(fragment);
}
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mAdapter);

MyAdapter:Adapter 是一个简单的容器。

public static class MyAdapter extends FragmentPagerAdapter {
    private List<Fragment> mFragmentList;

    public MyAdapter(FragmentManager fm) {
        super(fm);
        mFragmentList = new ArrayList<Fragment>();
    }

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

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

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

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

CustomFragment : 放置每个 fragment 的通用方法。

public abstract class CustomFragment extends Fragment {
    public abstract Fragment newInstance();
    public abstract String getPageTitle();
}

FirstFragment : 为每个 fragments inflate 不同的布局。

public class FirstFragment extends CustomFragment {

    @Override
    public Fragment newInstance() {
        Fragment f = new FirstFragment();
        return f;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        super.onCreateView(inflater, container, savedInstanceState);

        View view = inflater.inflate(R.layout.LAYOUT_ID_FOR_FIRST_FRAGMENT, container, false);

        // Some codes for layout such as findViewById

        return view;
    }

    @Override
    public String getPageTitle() {
        // return TITLE_FOR_FRAGMENT
    }
}

希望这个回答对您有所帮助。