【NGUI】grid下面的item的重复利用

http://blog.csdn.net/u012091672/article/details/21159075
解决的问题
使用grid放置item的时候，每次数据可能都不一样，但是每次都删除grid下面的节点，之后动态创建新的item是比较浪费的。

写个简单的工具函数，原理很简单。

1、先获得grid下面的可用item

2、根据data的大小进行初始化

3、每次在可用的item列表里面获取新的item，如果不够用了，就创建新的item

4、disable掉没用的item

附：每个grid下面预先要有一个名字包含“Template_”的模板item。这个模板不会被用，之前尝试过把这个模板也当做一个item正常使用，但是有些NGUI的widget会出现BUG。

[csharp] view plaincopy
using UnityEngine;  
using System.Collections.Generic;  
//qq group :333417608  
public class UITools  
{  
      
    /* usage: 
        List<GameObject> canUseList = UITools.GetCanUseItemList(gridRoot); 
        for (int i=0; i<totalData.Length; ++i) 
        { 
            GameObject go = UITools.GetNewItemObj(canUseList, gridRoot, prefab); 
            // do init 
        } 
        UITools.UnActiveUnuseItem(canUseList); 
 
        // prefab is the template 
     */   
  
    static public GameObject GetNewItemObj (List<GameObject> canUseList, GameObject root, GameObject prefab)  
    {  
        GameObject go = null;  
        if (canUseList.Count > 0) {  
            go = canUseList [0];  
            canUseList.RemoveAt (0);  
        } else {  
            go = NGUITools.AddChild (root, prefab);  
        }  
        NGUITools.SetActiveSelf (go, true);  
        return go;  
    }  
      
    static public T GetNewItemObj<T> (List<T> canUseList, GameObject root, GameObject prefab) where T : Component  
    {  
        T item = null;  
        if (canUseList.Count > 0) {  
            item = canUseList [0];  
            canUseList.RemoveAt (0);  
        } else {  
            item = NGUITools.AddChild (root, prefab).GetComponent<T>();  
        }  
        item.name = string.Format("{0:D3}", 0);  
        NGUITools.SetActiveSelf (item.gameObject, true);  
        return item;  
    }  
      
    static public List<GameObject> GetCanUseItemList (GameObject root)  
    {  
        List<GameObject> itemList = new List<GameObject> ();  
        Transform rootT = root.transform;  
        for (int i=0; i<rootT.childCount; ++i) {  
            GameObject go = rootT.GetChild (i).gameObject;  
            if (IsNotTemplateGameObject(go))  
            {  
                itemList.Add (go);  
            }  
        }  
        return itemList;  
    }  
      
    static public List<T> GetCanUseItemList<T> (GameObject root) where T : Component  
    {  
        List<T> childrenList = new List<T> ();  
        Transform rootT = root.transform;  
        for (int i=0; i<rootT.childCount; ++i) {  
            Transform child = rootT.GetChild (i);  
            T t = child.GetComponent<T> ();  
            if (t != null && IsNotTemplateGameObject(child.gameObject)) {  
                childrenList.Add (t);  
            }  
        }  
        return childrenList;  
    }  
      
    static public void UnActiveUnuseItem (List<GameObject> canUseList)  
    {  
        foreach (var item in canUseList) {  
            NGUITools.SetActiveSelf (item, false);  
        }  
    }  
      
    static public void UnActiveUnuseItem<T> (List<T> canUseList) where T : Component  
    {  
        foreach (var item in canUseList) {  
            NGUITools.SetActiveSelf (item.gameObject, false);  
        }  
    }  
      
    static private bool IsNotTemplateGameObject(GameObject go)  
    {  
        bool result = !go.name.ToLower().Contains("template_");  
        if (!result && go.activeSelf)  
        {  
            NGUITools.SetActiveSelf(go, false);  
        }  
        return result;  
    }  
}