RecyclerView实现自动平滑滚动(AutoScrollLoopView)

项目中需要一个Item可以自动循环滚动,既可以实现上下滚动,也可以实现左右滚动,主要在构造

setLayoutManager()时看传入的位置,是水平还是垂直

整体思路:给RecyclerView设置一个最大数,填充数据时对位置取余,然后用Handler发送,调用rv.smoothScrollToPosition(mAnimPosi); 方法,并设置自定义的管理器来控制速度

Adapter的编写

public class IndexLoopAdapter extends RecyclerView.Adapter<IndexLoopAdapter.MyViewHolder> {
    private List<IndexList.DataBean> dataList;

    public IndexLoopAdapter(List<IndexList.DataBean> dataList) {
        this.dataList = dataList;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_rv_index, parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull IndexLoopAdapter.MyViewHolder holder, int position) {
        if (dataList.size() != 0) {
            holder.ivArrow.setVisibility(View.VISIBLE);
            IndexList.DataBean dataBean = dataList.get(position % dataList.size());

            holder.tvPrice.setText(MathUtils.toTwo(dataBean.close / 1000f));
            holder.tvName.setText(dataBean.name);
            holder.tvIncrease.setText(MathUtils.toTwo(dataBean.incrate / 1000f) + "%");
        }else {
            holder.ivArrow.setVisibility(View.INVISIBLE);
        }

    }

    @Override
    public int getItemCount() {
        return Integer.MAX_VALUE;
    }


    public class MyViewHolder extends RecyclerView.ViewHolder {

        public TextView tvPrice, tvName, tvIncrease;
        private ImageView ivArrow;

        public MyViewHolder(View itemView) {
            super(itemView);
            tvPrice = itemView.findViewById(R.id.tvPrice);
            tvName = itemView.findViewById(R.id.tvName);
            tvIncrease = itemView.findViewById(R.id.tvIncrease);
            ivArrow = itemView.findViewById(R.id.ivArrow);

        }
    }
}

rv.setLayoutManager(new ScrollLinearLayoutManager(getContext()));
indexLoopAdapter = new IndexLoopAdapter(indexList);
rv.setAdapter(indexLoopAdapter);

定时发送

private Runnable animRun = new Runnable() {

    @Override
    public void run() {

        if (getUserVisibleHint()) {
            rvBottom.smoothScrollToPosition(mAnimPosi);
            mAnimPosi++;
        }
        handler.postDelayed(animRun, 3500);

    }
};

布局管理器

public class ScrollLinearLayoutManager extends LinearLayoutManager {

    private float mTime = 1500;

    public ScrollLinearLayoutManager(Context context) {
        super(context);
    }

    public ScrollLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
    }

    public ScrollLinearLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
        LinearSmoothScroller linearSmoothScroller = new LinearSmoothScroller(recyclerView.getContext()) {
            @Override
            protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
                return mTime / displayMetrics.densityDpi;
            }
        };

        linearSmoothScroller.setTargetPosition(position);
        startSmoothScroll(linearSmoothScroller);
    }

    public void setScrollTime(float time) {
        this.mTime = time;
    }
}

RecyclerView实现自动平滑滚动(AutoScrollLoopView)

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