unity通过改变相机视野实现UI元素放大缩小的效果

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;

public class MoveAndScroll : MonoBehaviour , IScrollHandler{
    public Camera mainCamera;
    private float view;

    public void OnScroll(PointerEventData eventData)
    {
        view = view + eventData.scrollDelta.y * 3f;//当鼠标中轮向上滚动时eventData.scrollDelta.y = 1.0 向下为-1;
        mainCamera.fieldOfView = Mathf.Clamp(view, 1f, 179f);//因为相机的视野只能为1-179；所以用Mathf.Clamp，将值限制一下
        t.text = eventData.scrollDelta.ToString();
    }
}

上面的代码绑在了一张UI图片上，要点是将该照片设为FirstSelected，好提供一个事件的焦点