unity的ui跟随鼠标移动

1、挂在需要跟随鼠标的UI上（Image，Text等）

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class UIFollowMouse : MonoBehaviour
{
    ///
    /// 需要跟随的物体
    ///
    private GameObject go;
    private void Awake()
    {
        go = gameObject;
    }
    private void OnEnable()
    {
        ChoosePivot();
        go.transform.position = Input.mousePosition;
    }
    ///
    /// 根据鼠标位置选择中心点，避免出现UI到屏幕外的情况
    ///
    private void ChoosePivot()
    {
        float width = Screen.width / 2;
        float height = Screen.height / 2;
        if (Input.mousePosition.x < width)
        {