RecyclerView和SwipeRefreshLayout

Question

我正在使用新RecyclerView-Layout的a SwipeRefreshLayout并经历了一种奇怪的行为.当滚动列表回到顶部时,有时顶部的视图会被切入.

如果我现在尝试滚动到顶部 - Pull-To-Refresh触发器.

如果我尝试删除Recycler-View周围的Swipe-Refresh-Layout,问题就消失了.它可以在任何手机上重现(不仅仅是L-Preview设备).

 <android.support.v4.widget.SwipeRefreshLayout
    android:id="@+id/contentView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:visibility="gone">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/hot_fragment_recycler"
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</android.support.v4.widget.SwipeRefreshLayout>

这是我的布局 - 行由RecyclerViewAdapter动态构建(此列表中有2个Viewtypes).

public class HotRecyclerAdapter extends TikDaggerRecyclerAdapter<GameRow> {

private static final int VIEWTYPE_GAME_TITLE = 0;
private static final int VIEWTYPE_GAME_TEAM = 1;

@Inject
Picasso picasso;

public HotRecyclerAdapter(Injector injector) {
    super(injector);
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position, int viewType) {
    switch (viewType) {
        case VIEWTYPE_GAME_TITLE: {
            TitleGameRowViewHolder holder = (TitleGameRowViewHolder) viewHolder;
            holder.bindGameRow(picasso, getItem(position));
            break;
        }
        case VIEWTYPE_GAME_TEAM: {
            TeamGameRowViewHolder holder = (TeamGameRowViewHolder) viewHolder;
            holder.bindGameRow(picasso, getItem(position));
            break;
        }
    }
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
    switch (viewType) {
        case VIEWTYPE_GAME_TITLE: {
            View view = inflater.inflate(R.layout.game_row_title, viewGroup, false);
            return new TitleGameRowViewHolder(view);
        }
        case VIEWTYPE_GAME_TEAM: {
            View view = inflater.inflate(R.layout.game_row_team, viewGroup, false);
            return new TeamGameRowViewHolder(view);
        }
    }
    return null;
}

@Override
public int getItemViewType(int position) {
    GameRow row = getItem(position);
    if (row.isTeamGameRow()) {
        return VIEWTYPE_GAME_TEAM;
    }
    return VIEWTYPE_GAME_TITLE;
}

这是适配器.

   hotAdapter = new HotRecyclerAdapter(this);

    recyclerView.setHasFixedSize(false);
    recyclerView.setAdapter(hotAdapter);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    contentView.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            loadData();
        }
    });

    TypedArray colorSheme = getResources().obtainTypedArray(R.array.main_refresh_sheme);
    contentView.setColorSchemeResources(colorSheme.getResourceId(0, -1), colorSheme.getResourceId(1, -1), colorSheme.getResourceId(2, -1), colorSheme.getResourceId(3, -1));

和Fragment包含的代码Recycler和SwipeRefreshLayout.

如果其他人经历过这种行为并解决了它或者至少找到了它的原因？

Answer 1

写下面的代码中addOnScrollListener的RecyclerView

像这样:

    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener(){
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            int topRowVerticalPosition =
                    (recyclerView == null || recyclerView.getChildCount() == 0) ? 0 : recyclerView.getChildAt(0).getTop();
            swipeRefreshLayout.setEnabled(topRowVerticalPosition >= 0);

        }

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
        }
    });

Answer 2

在您使用此解决方案之前:RecyclerView尚未完成,请不要在生产中使用它,除非您喜欢我!

至于2014年11月,RecyclerView中仍然存在导致canScrollVertically过早返回错误的错误.此解决方案将解决所有滚动问题.

解决方案的下降:

public class FixedRecyclerView extends RecyclerView {
    public FixedRecyclerView(Context context) {
        super(context);
    }

    public FixedRecyclerView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public FixedRecyclerView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    public boolean canScrollVertically(int direction) {
        // check if scrolling up
        if (direction < 1) {
            boolean original = super.canScrollVertically(direction);
            return !original && getChildAt(0) != null && getChildAt(0).getTop() < 0 || original;
        }
        return super.canScrollVertically(direction);

    }
}

您甚至不需要替换RecyclerView代码FixedRecyclerView,替换XML标记就足够了!(确保在RecyclerView完成后,转换将快速而简单)

说明:

基本上,canScrollVertically(boolean)过早返回false,所以我们检查是否RecyclerView一直滚动到第一个视图的顶部(第一个孩子的顶部将为0),然后返回.

编辑:如果你不想RecyclerView出于某种原因扩展,你可以扩展SwipeRefreshLayout和覆盖该canChildScrollUp()方法并将检查逻辑放在那里.

EDIT2: RecyclerView已经发布,到目前为止还没有必要使用此修复程序.

Answer 3

我最近遇到了同样的问题.我尝试了@Krunal_Patel建议的方法,但它在我的Nexus 4中大部分时间工作,并且在三星galaxy s2中根本不起作用.在调试时,对于RecyclerView,recyclelerView.getChildAt(0).getTop()始终不正确.因此,在经过各种方法之后,我想我们可以利用LayoutManager的方法findFirstCompletelyVisibleItemPosition()来预测RecyclerView的第一项是否可见,以启用SwipeRefreshLayout.Find下面的代码.希望它可以帮助有人试图解决同样的问题.干杯.

    recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {

        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        }

        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            swipeRefresh.setEnabled(linearLayoutManager.findFirstCompletelyVisibleItemPosition() == 0);
        }
    });

Answer 4

这就是我在我的案例中解决这个问题的方法.对于那些最终在这里寻找与此类似的解决方案的人来说,这可能是有用的.

recyclerView.addOnScrollListener(new OnScrollListener()
    {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy)
        {
            // TODO Auto-generated method stub
            super.onScrolled(recyclerView, dx, dy);
        }

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState)
        {
            // TODO Auto-generated method stub
            //super.onScrollStateChanged(recyclerView, newState);
            int firstPos=linearLayoutManager.findFirstCompletelyVisibleItemPosition();
            if (firstPos>0)
            {
                swipeLayout.setEnabled(false);
            }
            else {
                swipeLayout.setEnabled(true);
            }
        }
    });

我希望这肯定可以帮助那些正在寻找类似解决方案的人.