android - Viewpager 自动滚动没有处理程序 postdelayed 和 setcurrentitem

Question

我想在不使用 setCurrentItem() 函数的情况下实现自动 viewpager 滚动。因为当我将 setcurrentitem() 与 handler.postdelayed() 一起使用时，它会在设置下一个项目后保持不变。我想要一个像 recyclerview 一样的平滑滚动。用viewpager可以实现吗？

Answer 1

你可以用 ViewPager 来做。最好的轮播是使用recylerview。但是你需要先自定义 LayoutManager 来像轮播一样减慢速度

创建回收站视图

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

然后创建CustomLayoutManager来改变recyclerview滚动的速度

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 Runnable

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);
            }
        }
    };