如何在Unity中使UI元素在Y轴上可拖动？

using UnityEngine;
using UnityEngine.EventSystems;

public class DraggableUI : MonoBehaviour, IPointerDownHandler, IDragHandler
{
    private RectTransform rectTransform;
    private Vector2 pointerOffset;

    private void Awake()
    {
        rectTransform = GetComponent<RectTransform>();
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        // 计算鼠标或触摸事件位置与UI元素位置的偏移量
        pointerOffset = rectTransform.anchoredPosition - eventData.position;
    }

    public void OnDrag(PointerEventData eventData)
    {
        // 更新UI元素的Y轴位置
        rectTransform.anchoredPosition = new Vector2(rectTransform.anchoredPosition.x, eventData.position.y + pointerOffset.y);
    }
}