ViewPager自动滚动，而无需处理程序邮政和setCurrentItem

Question

我想在不使用setCurrentItem（）函数的情况下实现自动视图滚动。因为当我将setCurrentItem（）与handler.postdelayed（）使用后，它将在设置下一个项目后保持。而且我想要像回收瓶一样光滑的卷轴。可以使用ViewPager实现它吗？

Answer 1

您可以使用ViewPager进行操作。最好的旋转木马是使用Recylerview。但是您需要首先自定义Layoutmanager，以减慢速度，例如轮旋

创建recyclerview

CustomLayoutManager layoutManager = new CustomLayoutManager(getActivity());
layoutManager.setSpeed(1500f);
layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);

然后创建CustomLayoutManager，以更改RecylCerview Scroll的速度

public class CustomLayoutManager extends LinearLayoutManager {
    private float MILLISECONDS_PER_INCH = 1100f;
    private Context mContext;
    public CustomLayoutManager(Context context) {
        super(context);
        mContext = context;
    }
    @Override
    public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, final int position) {
        LinearSmoothScroller smoothScroller = new LinearSmoothScroller(mContext) {
                    @Override
                    public PointF computeScrollVectorForPosition(int targetPosition) {
                        return CustomLayoutManager.this.computeScrollVectorForPosition(targetPosition);
                    }
                    @Override
                    protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
                        return MILLISECONDS_PER_INCH/displayMetrics.densityDpi;
                    }
                };
        smoothScroller.setTargetPosition(position);
        startSmoothScroll(smoothScroller);
    }
    public void setSpeed(float speed){
        this.MILLISECONDS_PER_INCH = speed;
    }
}

然后在您的活动或片段中，创建可运行的

Runnable runNews = new Runnable() {
        @Override
        public void run() {
            try {
                top_new_rview.smoothScrollToPosition(++counter);
                handler.postDelayed(this, replay);
            } catch (Exception e) {
                handler.removeCallbacks(runNews);
                onError(getActivity(), e);
            }
        }
    };