RecyclerView和SwipeRefreshLayout [英] RecyclerView and SwipeRefreshLayout

问题描述

我使用的是新的RecyclerView-布局在SwipeRefreshLayout，并经历了一个奇怪的现象。当滚动列表回到顶端有时在顶部视图被切

I'm using the new RecyclerView-Layout in a SwipeRefreshLayout and experienced a strange behaviour. When scrolling the list back to the top sometimes the view on the top gets cut in.

如果我现在尝试滚动到顶部 - 拉要刷新的触发器。

If i try to scroll to the top now - the Pull-To-Refresh triggers.

如果我尝试并删除刷刷新，布局各地的回收站，查看问题消失了。而其上的任何电话（不仅是L- preVIEW设备）可再现。

If i try and remove the Swipe-Refresh-Layout around the Recycler-View the Problem is gone. And its reproducable on any Phone (not only L-Preview devices).

 <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（2 Viewtypes在名单）动态生成。

That's my layout - the rows are built dynamically by the RecyclerViewAdapter (2 Viewtypes in this List).

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;
}

这里的适配器。

Here's the Adapter.

   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));

和包含回收站和SwipeRefreshLayout片段的code。

And the code of the Fragment containing the Recycler and the SwipeRefreshLayout.

如果任何人都经历了这种行为，并解决它，或者至少找到了原因呢？

If anyone else has experienced this behaviour and solved it or at least found the reason for it?

推荐答案

<打击> 在使用此解决方案： RecyclerView尚未完成，尽量不要将其用于生产，除非你像我一样！

Before you use this solution: RecyclerView is not complete yet, TRY NOT TO USE IT IN PRODUCTION UNLESS YOU'RE LIKE ME!

至于2014年11月，还在RecyclerView错误，将导致 canScrollVertically 来pmaturely返回false $ P $。该解决方案将解决所有问题的滚动

As for November 2014, there are still bugs in RecyclerView that would cause canScrollVertically to return false prematurely. This solution will resolve all scrolling problems.

在溶液中的降：

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);

    }
}

您甚至不需要更换 RecyclerView 在code与 FixedRecyclerView ，替换XML标签就足够了！ （该确保当RecyclerView完成后，过渡将是快速和简单的）

You don't even need to replace RecyclerView in your code with FixedRecyclerView, replacing the XML tag would be sufficient! (The ensures that when RecyclerView is complete, the transition would be quick and simple)

说明：

基本上， canScrollVertically（布尔）返回false太早，所以我们检查 RecyclerView 滚动所有的方式向第一视图（其中第一子的顶端。将0），然后返回的顶

Basically, canScrollVertically(boolean) returns false too early,so we check if the RecyclerView is scrolled all the way to the top of the first view (where the first child's top would be 0) and then return.

编辑： 如果你不希望延长 RecyclerView 出于某种原因，你可以扩展 SwipeRefreshLayout 并覆盖 canChildScrollUp（）的方法，并把检查逻辑在里面。

And if you don't want to extend RecyclerView for some reason, you can extend SwipeRefreshLayout and override the canChildScrollUp() method and put the checking logic in there.

EDIT2： <击> RecyclerView已被释放，至今也没有必要使用此修复程序。

这篇关于RecyclerView和SwipeRefreshLayout的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！