Unity 从工具栏上拖拽生成物体

1.新建场景，建立工具栏。 2.在Resources文件夹下建立预制件person。 3.建立脚本DragSpawn.cs，挂载到要拖拽的按钮上。

拖拽三维实体见：https://blog.csdn.net/zouxin_88/article/details/89237172

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

public class DragSpawn : MonoBehaviour, IPointerDownHandler
{
    //正在拖拽的物体
    private GameObject _objDragSpawning;

    //是否正在拖拽
    private bool _isDragSpawning = false;

    // Update is called once per frame
    void Update()
    {
#if UNITY_EDITOR
        if (_isDragSpawning)
        {
            //刷新位置
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            _objDragSpawning.transform.position = ray.GetPoint(10);

            //结束拖拽
            if (Input.GetMouseButtonUp(0))
            {
                _isDragSpawning = false;
                _objDragSpawning = null;
            }
        }
#endif

#if UNITY_ANDROID
        if (_isDragSpawning)
        {
            if (Input.touchCount == 1)
            {
                if (Input.touches[0].phase == TouchPhase.Moved)
                {
                    Vector3 ptMouse = Input.touches[0].position;

                    //刷新位置
                    Ray ray = Camera.main.ScreenPointToRay(ptMouse);
                    _objDragSpawning.transform.position = ray.GetPoint(10);
                }

                if (Input.touches[0].phase == TouchPhase.Ended)
                {
                    _isDragSpawning = false;
                    _objDragSpawning = null;
                }
            }
        }
#endif
    }

    //按下鼠标时开始生成实体
    public void OnPointerDown(PointerEventData eventData)
    {
        GameObject prefab = Resources.Load("person");
        if (prefab != null)
        {
            _objDragSpawning = Instantiate(prefab);
            _isDragSpawning = true;
        }

    }

}