Question

我收到编译时错误The method getLastCustomNonConfigurationInstance() of type TopRatedFragment must override or implement a supertype method

TopRatedFragment.java：

public class TopRatedFragment extends Fragment {

    private CurlView mCurlView;


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

        View rootView = inflater.inflate(R.layout.fragment_top_rated, container, false);

        int index = 0;
        if (getLastCustomNonConfigurationInstance() != null) {
            index = (Integer) getLastCustomNonConfigurationInstance();
        }

        mCurlView = (CurlView)rootView.findViewById(R.id.curl);
        mCurlView.setPageProvider(new PageProvider());
        mCurlView.setSizeChangedObserver(new SizeChangedObserver());
        mCurlView.setCurrentIndex(index);
        mCurlView.setBackgroundColor(0xFF202830);



        return rootView;
    }

    @Override
    public Object getLastCustomNonConfigurationInstance() { ---> getting compile error
        return mCurlView.getCurrentIndex();
    }

我正在操作栏标签中进行页面卷曲。所以我只是将FragmentActivity代码发送到Fragment。getLastCustomNonConfigurationInstance()方法属于FragmentActivity。这就是我收到错误的原因。

我不知道如何以正确的方式解决这个错误。任何人都可以帮助我。

编辑：我肯定需要那个方法。顺便说一下如果删除覆盖，那么在运行时会得到空指针异常。

Answer 1

将配置方法及其调用保留在FragmentActivity中，并创建一个接口以在Fragment中获取/设置索引。

在Fragment：

中

public class TopRatedFragment extends Fragment
{
    public interface ISettings
    {
        public int getIndex();
        public void setIndex(int index);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState)
    {
        ...
        int index = ((ISettings) getActivity()).getIndex();
        ...
    }
    ...
}

在FragmentActivity：

public class MainActivity extends FragmentActivity
    implements TopRatedFragment.ISettings
{
    private int mCurlViewIndex = 0;

    @Override
    public int getIndex()
    {
        return mCurlViewIndex;
    }

    @Override
    public void setIndex(int index)
    {
        mCurlViewIndex = index;
    }

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        ...
        if (getLastCustomNonConfigurationInstance() != null)
        {
            mCurlViewIndex = (Integer) getLastCustomNonConfigurationInstance();
        }
        ...
    }
    ...
}

Fragment类型的方法必须覆盖或实现超类型方法

1 个答案: