如何在fragment中嵌套使用viewpager

fragment1 Class One对应的布局文件 one.xml
android:id="@+id/one_vp"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

fragment1对应的类Class One:
public class One extends Fragment {

private List list = new ArrayList();

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.one, null);
return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
ViewPager vp = (ViewPager) getView().findViewById(R.id.one_vp);

list.add(new FragOne());//子fragment
list.add(new FragTwo());//子fragment

VpAdapter adapter = new VpAdapter(getChildFragmentManager(), list);
vp.setAdapter(adapter);
}
}

漏掉VpAdapter类了：
public class VpAdapter extends FragmentPagerAdapter {

private List list = new ArrayList();

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

public VpAdapter(FragmentManager fm, List list) {
super(fm);
this.list = list;
}

@Override
public Fragment getItem(int i) {
return list.get(i);
}

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

}