unity中用UGUI實現在UI界面鼠標旋轉三維物體

using UnityEngine;
using UnityEngine.EventSystems;

public class SpinWithMouse : MonoBehaviour, IDragHandler
{
    public Transform target;  //要旋轉的三維物體的Transform組件
    public float speed = 1f;

    void Start()
    {
        if (target == null) target = transform;
    }

    public void OnDrag(PointerEventData eventData)
    {
        target.localRotation = Quaternion.Euler(0f, -0.5f * eventData.delta.x * speed, 0f) * target.localRotation;
    }
}

 void OnMouseDrag()
    {
        axisX = -Input.GetAxis("Mouse X");
        axisY = Input.GetAxis("Mouse Y");
    }
    void Update()
    {
        if (Input.GetMouseButton(0))
        {
            this.transform.Rotate(new Vector3(-axisY* RotateSpeed, axisX* RotateSpeed, 0) * 0.5f, Space.World);
        }
        float fov = Camera.main.fieldOfView;
        fov+=Input.GetAxis("Mouse ScrollWheel")* Sensitive;
        fov = Mathf.Clamp(fov,miniView,maxView);
        Camera.main.fieldOfView = fov;
    }