使用RecyclerView在Android 2.2中的任何位置滚动Swip​​eRefreshLayout

Question

我的布局有问题,我在里面用RecyclerView创建了SwipeRefreshLayout.在android 4.2.2+中一切都运行良好,但在andorid 2.3.4我无法向上滚动,因为在RecyclerView中的任何地方它都会刷新,我必须向下滚动然后向上滚动.

这是我的代码:

<android.support.v4.widget.SwipeRefreshLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/forum_swipe_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/LVP"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:gravity="center" />
</android.support.v4.widget.SwipeRefreshLayout>

我发现了这个问题:https://code.google.com/p/android/issues/detail？id = 78191,但没有解决方案.知道怎么解决吗？

Answer 1

覆盖RecyclerView的方法 OnScrollStateChanged

 mRecyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {

            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                // TODO Auto-generated method stub
                //super.onScrollStateChanged(recyclerView, newState);
               try {
                   int firstPos = mLayoutManager.findFirstCompletelyVisibleItemPosition();
                   if (firstPos > 0) {
                       mSwipeRefreshLayout.setEnabled(false);
                   } else {
                       mSwipeRefreshLayout.setEnabled(true);
                       if(mRecyclerView.getScrollState() == 1)
                           if(mSwipeRefreshLayout.isRefreshing())
                            mRecyclerView.stopScroll();
                   }

               }catch(Exception e) {
                   Log.e(TAG, "Scroll Error : "+e.getLocalizedMessage());
               }
            }

检查刷卡刷新是否刷新并尝试向上滚动然后出现错误,因此当刷卡刷新正在进行时我尝试这样做 mRecyclerView.stopScroll();

Answer 2

不幸的是,这是一个已知问题,将在未来版本中修复.

https://code.google.com/p/android/issues/detail?id=78191

同时,如果您需要紧急修复,覆盖canChildScrollUp在SwipeRefreshLayout.java和调用recyclerView.canScrollVertically(mTarget, -1).因为canScrollVertically是在姜饼之后添加的,所以你还需要复制该方法并在recyclerview中实现.

或者,如果您使用的是LinearLayoutManager,则可以调用findFirstCompletelyVisibleItemPosition.

抱歉给你带来不便.

Answer 3

我使用以下代码修复了向上滚动问题:

private RecyclerView.OnScrollListener scrollListener = new RecyclerView.OnScrollListener() {
    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        LinearLayoutManager manager = ((LinearLayoutManager)recyclerView.getLayoutManager());
        boolean enabled =manager.findFirstCompletelyVisibleItemPosition() == 0;
        pullToRefreshLayout.setEnabled(enabled);
    }
};

然后你需要使用setOnScrollListener或addOnScrollListener取决于你是否有一个或多个听众.

Answer 4

您可以像这样重写 SwipeRefreshLayout 中的 canChildScrollUp() 方法：

public boolean canChildScrollUp() {
    if (mTarget instanceof RecyclerView) {
        final RecyclerView recyclerView = (RecyclerView) mTarget;
        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
        if (layoutManager instanceof LinearLayoutManager) {
            int position = ((LinearLayoutManager) layoutManager).findFirstCompletelyVisibleItemPosition();
            return position != 0;
        } else if (layoutManager instanceof StaggeredGridLayoutManager) {
            int[] positions = ((StaggeredGridLayoutManager) layoutManager).findFirstCompletelyVisibleItemPositions(null);
            for (int i = 0; i < positions.length; i++) {
                if (positions[i] == 0) {
                    return false;
                }
            }
        }
        return true;
    } else if (android.os.Build.VERSION.SDK_INT < 14) {
        if (mTarget instanceof AbsListView) {
            final AbsListView absListView = (AbsListView) mTarget;
            return absListView.getChildCount() > 0
                    && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
                            .getTop() < absListView.getPaddingTop());
        } else {
            return mTarget.getScrollY() > 0;
        }
    } else {
        return ViewCompat.canScrollVertically(mTarget, -1);
    }
}