Question

请帮帮我解决？

我有Activity ViewPager和RecyclerViewFragment个，RecyclerFragment每个都包含动态CardView。

ViewPager适配器的代码：

public class CustomFragmentPagerAdapter extends FragmentStatePagerAdapter {

    private Board board;
    private long boardID;

    public CustomFragmentPagerAdapter(FragmentManager fm, Board board, long id) {
        super(fm);
        this.board = board;
        this.boardID = id;
    }

    @Override
    public int getCount() {
        return 5;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return board.getMyLists().get(position).getName();
    }

    //Here I define fragment, int position - is a position of Fragment in ViewPager
    @Override
    public Fragment getFragment( int position) {
        **return RecyclerViewFragment.newInstance(boardID, position);**
    }
}

接下来是片段的新实例：

public static RecyclerViewFragment newInstance(long id, int listPosition){
    Bundle args = new Bundle();
    args.putLong(BUNDLE_ID, id);
    args.putInt(BUNDLE_LIST_POSITION, listPosition);
    RecyclerViewFragment fragment = new RecyclerViewFragment();
    fragment.setArguments(args);
    return fragment;
}

我通过Bundle存储 Fragment的位置 - listPosition

然后我通过getArguments()

在OnCreateView中获得该位置

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    boardID = this.getArguments().getLong(BUNDLE_ID);
    listPosition = this.getArguments().getInt(BUNDLE_LIST_POSITION, 0);
    return inflater.inflate(R.layout.fragment_recyclerview, container, false);
}

所以问题是，当我从getArguments（）获得int-Position时，它有下一个序列 - 1,2,3,4,0。但它按此顺序写入 - 0,1,2,3,4

您可能认为这并不重要，但Realm ORM确实可以逆转。当我从DB获得有关动态CardViews的信息时，Realm从第0个片段开始，而getArguments（）从1开始。那个东西抛出

ArrayIndexOutOfBoundsException异常

[更新] 我将Log.d添加到newInstance和OnCreateView

public static RecyclerViewFragment newInstance(long id, int listPosition){
    Bundle args = new Bundle();
    args.putLong(BUNDLE_ID, id);
    Log.d(TAG, listPosition + " Before put");
    args.putInt(BUNDLE_LIST_POSITION, listPosition);
    Log.d(TAG, listPosition + " After put");
    RecyclerViewFragment fragment = new RecyclerViewFragment();
    fragment.setArguments(args);
    return fragment;
}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    tinyDB = new TinyDB(getContext());
    boardPosition = tinyDB.getInt("boardPosition");
    boardID = this.getArguments().getLong(BUNDLE_ID);
    listPosition = this.getArguments().getInt(BUNDLE_LIST_POSITION, 0);
    Log.d(TAG, listPosition + " Get ");
    return inflater.inflate(R.layout.fragment_recyclerview, container, false);
}

在LogCat中我接下来：

06-12 00:37:46.188 25265-25265/com.treggo.flexible D/mLogs: 0 Before put
06-12 00:37:46.188 25265-25265/com.treggo.flexible D/mLogs: 0 After put
06-12 00:37:46.188 25265-25265/com.treggo.flexible D/mLogs: 1 Before put
06-12 00:37:46.188 25265-25265/com.treggo.flexible D/mLogs: 1 After put
06-12 00:37:46.188 25265-25265/com.treggo.flexible D/mLogs: 2 Before put
06-12 00:37:46.188 25265-25265/com.treggo.flexible D/mLogs: 2 After put
06-12 00:37:46.189 25265-25265/com.treggo.flexible D/mLogs: 3 Before put
06-12 00:37:46.189 25265-25265/com.treggo.flexible D/mLogs: 3 After put
06-12 00:37:46.189 25265-25265/com.treggo.flexible D/mLogs: 4 Before put
06-12 00:37:46.189 25265-25265/com.treggo.flexible D/mLogs: 4 After put
06-12 00:37:46.190 25265-25265/com.treggo.flexible D/mLogs: 1 Get 
06-12 00:37:46.266 25265-25265/com.treggo.flexible D/mLogs: 2 Get 
06-12 00:37:46.322 25265-25265/com.treggo.flexible D/mLogs: 3 Get 
06-12 00:37:46.397 25265-25265/com.treggo.flexible D/mLogs: 4 Get 
06-12 00:37:46.452 25265-25265/com.treggo.flexible D/mLogs: 0 Get

P.S。为了绕过Exception，我设置了9个CardViews，而不是从Realm

中读取它

Answer 1

虽然我不知道如何实现列表位置的索引，但我认为它从1开始，而不是从0开始。

如果是这种情况，请在newInstance()方法中替换以下行：

args.putInt(BUNDLE_LIST_POSITION, listPosition);

用这个：

args.putInt(BUNDLE_LIST_POSITION, listPosition - 1);

getArguments（）。getInt（）从＆＃34; 1＆＃34;开始返回，而不是＆＃34; 0＆＃34;

1 个答案: