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android - RecyclerView中捕捉SmoothScroll的动画事件[Android]

问题描述

我有一个附加了 PageSnapHelper 的 GridLayout RecyclerView，它基本上就像一个垂直线性 RecyclerView （我继承了代码，不知道为什么这样做）。目标是突出显示当前在视图中居中的项目。滚动是从由两个菜单项驱动的代码完成的，以模拟从遥控器前进和后退。滚动视图工作正常。问题似乎是，当我收听滚动事件结束时，会出现动画，这会弄乱我的代码以在项目周围绘制突出显示。这是我用来根据菜单项滚动视图的代码：

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    //Get which arrow was pressed
    int id = item.getItemId();
   //Get count of items
    int itemCount = recyclerView.getAdapter().getItemCount();



    //Condition to moving down the list
    if (id == R.id.next) {
        //Make sure we're within bounds of the of the view from the top
        if(count>=itemCount-1) {
            return super.onOptionsItemSelected(item);
        }
        //Increment to count to next ViewHolder
        count++;
    //Condition for moving up list
    } else if (id == R.id.prev) {
        //Make sure we're within bounds
        if(count == 0){
            return super.onOptionsItemSelected(item);
        }
        //Decremennt to previous ViewHolder
        count--;
    }

    //Scroll the RecyclerView to the position we want
    layoutManager.setIsNext(id == R.id.next);
    recyclerView.smoothScrollToPosition(count);

    //If the item is already in view, then no scroll event is necessary and we can access the ViewHolder
    HighlightViewHolder(count);

    //In the event that the ViewHolder is off-screen listen for the end of the scrolling event to ensure the ViewHolder
    //is created and in correct position on the screen
    RecyclerView.OnScrollListener scrollListener = new RecyclerView.OnScrollListener() {

        //Add a listener to that looks out for when the scrolling is complete
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);

            Log.i("ScrollListener", "Scrolling has ended");
            HighlightViewHolder(count);
            recyclerView.removeOnScrollListener(this);

        }
    };

    recyclerView.addOnScrollListener(scrollListener);

    return super.onOptionsItemSelected(item);

当应用程序第一次启动并且我按下前进按钮时，第一项突出显示就好了： 在此处输入图像描述

在下一个选择中，参与滚动事件是我遇到问题的地方：在此处输入图像描述

我期望发生的是，当滚动事件结束时，该项目处于其中心位置。根据我所看到的，我认为还有一些动画事件仍在发生，我应该寻找完成。我的突出显示代码依赖于有问题的视图位于其预期位置。我是 android 新手，我对 RecyclerView 动画的搜索将我带到了 ItemAnimator。但是阅读文档我不确定这是否是我正在寻找的。有任何想法吗？

标签： androidkotlinandroid-recyclerviewsmooth-scrollingpagersnaphelper

解决方案

我找不到与我要查找的内容相关的任何事件，因此我继续使用处理程序在绘制高光之前等待任意时间。我这样更新了监听器：

//Add a listener to that looks out for when the scrolling is complete
            @Override
            public void onScrolled(final RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                Handler handler = new Handler();
                Runnable task = new Runnable() {
                    @Override
                    public void run() {
                        HighlightViewHolder(count);
                    }
                };

                handler.postDelayed(task, 500);
                recyclerView.removeOnScrollListener(this);
            }

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