Unity物品栏拖拽物品移动交换物品所在物品栏位置

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using UnityEngine.EventSystems;

public class ChangeEquip : MonoBehaviour,IBeginDragHandler,IEndDragHandler,IDragHandler {

//得到画布

Transform canvas;

//要拖动物体的原始父物体

private Transform originalParent;

//组件

private CanvasGroup canvasGroup;

//偏移量

Vector3 offset;

void Start () {

canvas = GameObject.Find ("Canvas").transform;

canvasGroup = GetComponent<CanvasGroup> ();

}

void Update () {

}

#region 开始拖拽

public void OnBeginDrag (PointerEventData eventData)

{

originalParent = transform.parent;

//改变要拖拽物体的父物体为画布，这样物体就会显示在所有背包的最前面

transform.SetParent(canvas);

offset = transform.position - Input.mousePosition;

//在拖拽控件时，鼠标射线可以穿透控件，并被下面的控件所接受

canvasGroup.blocksRaycasts = false;

}

#endregion

#region IDragHandler implementation

public void OnDrag (PointerEventData eventData)

{

transform.position = Input.mousePosition + offset;

}

#endregion

#region IEndDragHandler implementation

public void OnEndDrag (PointerEventData eventData)

{

//鼠标拖拽控件时进入的物体

Transform obj;

//如果鼠标在背包的外面

if (eventData.pointerEnter == null) {

//把拖拽的物体放回到原来的位置

transform.SetParent (originalParent);

transform.localPosition = Vector3.zero;

canvasGroup.blocksRaycasts = true;

return;

} else {

obj = eventData.pointerEnter.transform;

}

//需要判断OBJ是什么控件

switch(obj.tag){

case "item":

{

Transform temp = obj.parent;

obj.SetParent (originalParent);

transform.SetParent (temp);

obj.localPosition = Vector3.zero;

}

break;

case "cell":

{

//如果有一个物体

if (obj.childCount == 1) {

Transform child = obj.GetChild (0);

child.SetParent (originalParent);

transform.SetParent (obj);

child.localPosition = Vector3.zero;

} else {//如果没有物体

transform.SetParent (obj);

}

}

break;

default:

{

transform.SetParent (originalParent);

}

break;

}

transform.localPosition = Vector3.zero;

canvasGroup.blocksRaycasts = true;

}

#endregion

}