最笨的将一物体在屏幕范围内拖动

using System;using System.Collections;using System.Collections.Generic;using UnityEngine;using UnityEngine.EventSystems;using UnityEngine.UI;public class TestDrag : MonoBehaviour ,IDragHandler{    public Image map;    float map_width;    float map_heigh;    float stansrdPosX;    float stansrdPosY;    void Start()    {        // 被拖动物体的宽和高        map_width = gameObject.GetComponent<RectTransform>().sizeDelta.x;        map_heigh = gameObject.GetComponent<RectTransform>().sizeDelta.y;        Debug.Log(map_width);        Debug.Log(map_heigh);        stansrdPosX = map_width / 2;        stansrdPosY = map_heigh / 2;    }    public void OnDrag(PointerEventData eventData)    {        // 鼠标位置        float posX = Input.mousePosition.x;        float posY = Input.mousePosition.y;        if (posX > stansrdPosX && posX < (1366- stansrdPosX) && posY > stansrdPosY && posY < (768- stansrdPosY))        {            gameObject.transform.position = Input.mousePosition;        }        if (posX <= stansrdPosX)        {            posX = stansrdPosX + 5;        }        if (posX >= (1366 - stansrdPosX))        {            posX = (1366 - stansrdPosX) - 5;        }        if (posY <= stansrdPosY)        {            posY = stansrdPosY + 5;        }        if (posY >= (768 - stansrdPosY))        {            posY = (768 - stansrdPosY) - 5;        }        gameObject.transform.position = new Vector2(posX, posY);    }}