Unity 简单实现物体拖拽

using System.Collections;

using System.Collections.Generic;

using UnityEngine.UI;

using System;

using UnityEngine.EventSystems;

public class durg : MonoBehaviour

{

    private int mode = 0;

    GameObject gameObj;

    public GameObject btnTurn;

    Vector3 pos;

    Ray ray;

    RaycastHit hitInfo;

LayerMask mask = 1 << 8;

    public EventSystem es;

    public GraphicRaycaster gr;

    void Awake()

    {

btnTurn.transform.GetChild(1).GetComponent().onClick.AddListener(BtnTurnRight);

btnTurn.transform.GetChild(2).GetComponent

().onClick.AddListener(BtnTurnLeft);

        btnTurn.gameObject.SetActive(false);

    }

    private void BtnTurnRight()

    {

        gameObj.transform.eulerAngles += new Vector3(0, 15, 0);

    }

    private void BtnTurnLeft()

    {

        gameObj.transform.eulerAngles += new Vector3(0, -15, 0);

    }

    void Update()

    {

        if (Input.GetMouseButtonDown(0))

        {

            ray = Camera.main.ScreenPointToRay(Input.mousePosition);

            if (Physics.Raycast(ray, out hitInfo))

            {

                if (hitInfo.transform.gameObject.tag == "Furniture")

                {

                        gameObj = hitInfo.transform.gameObject;

                        mode = 1;

                }

            }

        }

        if (Input.GetMouseButton(0))

        {

            if (check())

                return;

            else

            {

                ray = Camera.main.ScreenPointToRay(Input.mousePosition);

                if (Physics.Raycast(ray, out hitInfo, Mathf.Infinity, mask.value))

                {

                    if (mode == 1)

                    {

                        gameObj.transform.position = hitInfo.point;

                        btnTurn.gameObject.SetActive(false);

                    }

                }

            }

        }

        if (Input.GetMouseButtonUp(0))

        {

            mode = 0;

            if (check())

                return;

            else

            {

                ray = Camera.main.ScreenPointToRay(Input.mousePosition);

                if (Physics.Raycast(ray, out hitInfo))

                {

                    if (hitInfo.transform.gameObject.tag == "Furniture")

                    {

                        btnTurn.gameObject.SetActive(true);

                        Vector3 screenPos = Camera.main.WorldToScreenPoint(gameObj.transform.position);

btnTurn.GetComponent().position = screenPos;

                    }

                    else

                    {

                        btnTurn.gameObject.SetActive(false);

                    }

                }

            }

        }

    }

    bool check()

    {

        PointerEventData eventData = new PointerEventData(es);

        eventData.pressPosition = Input.mousePosition;

        eventData.position = Input.mousePosition;

        List list = new List();

        gr.Raycast(eventData, list);

        return list.Count > 0;

    }

}