RecyclerView点击Item自动居中

Use

val centerLayoutManager =
        CenterLinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
    rv.layoutManager = centerLayoutManager
//传入pos
private fun scrollCenter(pos: Int) {
    centerLayoutManager?.smoothScrollToPosition(rvDate,
        RecyclerView.State(),
        pos)
}

LinearLayoutManager

public class CenterLinearLayoutManager extends LinearLayoutManager {

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

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

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

@Override
public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
    RecyclerView.SmoothScroller smoothScroller = new CenterSmoothScroller(recyclerView.getContext());
    smoothScroller.setTargetPosition(position);
    startSmoothScroll(smoothScroller);
}

private static class CenterSmoothScroller extends LinearSmoothScroller {

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

    //计算位置
    @Override
    public int calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int snapPreference) {
        return (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2);
    }

    //滚动速度
    @Override
    protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
        return 100f / displayMetrics.densityDpi;
    }

}
}