已在Recyclerview中设置OnFlingListener的实例

Question

我在我的Android应用程序中使用了RecyclerView.我在RecyclerView中有很多卡片视图,这样一次只能向用户显示1张卡片视图.用户必须滑动才能看到下一张卡片.

我遇到了一个问题,当用户进行滑动时,recyclerview会滚动到最后.相反,我需要的是当用户滑动时,如本文所述,向用户显示下一张卡片.

如何在水平回收视图上进行滑动只会将下一个项目放入视图中 - Android

SnapHelper snapHelper = new PagerSnapHelper();
snapHelper.attachToRecyclerView(recyclerView);

我尝试了上面链接中提到的答案.但是当用户刷卡时我得到一个例外.

请帮我解决一下.

错误

java.lang.IllegalStateException: An instance of OnFlingListener already set.
    at android.support.v7.widget.SnapHelper.setupCallbacks(SnapHelper.java:114)
    at android.support.v7.widget.SnapHelper.attachToRecyclerView(SnapHelper.java:102)
    at com.abc.ui.trm.TrCard.setupCardView(TrCard.java:62)
    at com.abc.ui.trm.TrCard.setupCardView(TrCard.java:29)
    at com.abc.ui.core.card.BaseCardView.processCardView(BaseCardView.java:134)
    at com.abc.ui.card.CardRecyclerAdapter.onViewAttachedToWindow(CardRecyclerAdapter.java:398)
    at android.support.v7.widget.RecyclerView.dispatchChildAttached(RecyclerView.java:6758)
    at android.support.v7.widget.RecyclerView$5.addView(RecyclerView.java:696)
    at android.support.v7.widget.ChildHelper.addView(ChildHelper.java:107)
    at android.support.v7.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:7697)
    at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:7655)
    at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:7643)
    at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1539)
    at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1488)
    at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:585)
    at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3506)
    at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3254)
    at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3767)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at com.abc.ui.core.refresh.LegacySwipeRefreshLayout.onLayout(LegacySwipeRefreshLayout.java:337)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1079)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:1193)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
    at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
    at com.android.internal.policy.DecorView.onLayout(DecorView.java:822)
    at android.view.View.layout(View.java:18799)
    at android.view.ViewGroup.layout(ViewGroup.java:5952)

Answer 1

我设法通过添加这一行来解决这个问题

recyclerView.setOnFlingListener(null); 

之前

snapHelper.attachToRecyclerView(recyclerView);

Answer 2

发生这种情况是因为您SnapPagerHelper以某种方式设置了两次。请注意，如果你有一个RecyclerViewinside another RecyclerView，这应该只发生在彼此的构造函数或 Kotlin 的init {}块中（每个项目一次）。
我的情况与您的情况非常相似，因为我有一个大的垂直RecyclerView和一个小的RecyclerView内部。

将导致异常的代码：

 fun bind(value: ArrayList<Item>) {
    listAdapter = ItemCellDelegate(value)

    val manager = LinearLayoutManager(itemView.context)
    manager.orientation = LinearLayoutManager.HORIZONTAL

    horizontalRecyclerView?.apply {
        layoutManager = manager
        adapter = listAdapter
        setHasFixedSize(true)
    }

    val snapHelper: SnapHelper = PagerSnapHelper()
    snapHelper.attachToRecyclerView(horizontalRecyclerView)

}

使用init {}块的正确代码：

init {
    val snapHelper: SnapHelper = PagerSnapHelper()
    snapHelper.attachToRecyclerView(horizontalRecyclerView)
}

Answer 3

您要做的就是放置

SnapHelper snapHelper = new PagerSnapHelper();
snapHelper.attachToRecyclerView(recyclerView);

里面onCreateViewHolder而不是onBindViewHolder

Answer 4

您可以先在RecyclerView上检查OnFlingListener，然后再添加它

if (recycler.getOnFlingListener() == null)
        snapHelper.attachToRecyclerView(recycler);