ScrollVIEW 2000个ITEM不会卡

</pre><pre name="code" class="csharp">using UnityEngine;using System.Collections.Generic; public class UIWrapGrid : MonoBehaviour{    Transform mTrans;    UIPanel mPanel;    UIScrollView mScroll;    bool mHorizontal = false;    bool mFirstTime = true;    List<Transform> mChildren = new List<Transform>();     /// <summary>    /// Initialize everything and register a callback with the UIPanel to be notified when the clipping region moves.    /// </summary>     protected virtual void Start () {        InitGrid();        mFirstTime = false;    }     /// <summary>    /// Cache the scroll view and return 'false' if the scroll view is not found.    /// </summary>    public void InitGrid() {        mTrans = transform;        mPanel = NGUITools.FindInParents<UIPanel>(gameObject);        mScroll = mPanel.GetComponent<UIScrollView>();         if (mScroll != null) {            mScroll.GetComponent<UIPanel>().onClipMove = OnMove;        }         mChildren.Clear();        for (int i = 0; i < mTrans.childCount; ++i)            mChildren.Add(mTrans.GetChild(i));         // Sort the list of children so that they are in order        mChildren.Sort(UIGrid.SortByName);         if (mScroll == null) return;        if (mScroll.movement == UIScrollView.Movement.Horizontal) mHorizontal = true;        else if (mScroll.movement == UIScrollView.Movement.Vertical) mHorizontal = false;         WrapContent();    }     /// <summary>    /// Callback triggered by the UIPanel when its clipping region moves (for example when it's being scrolled).    /// </summary>     protected virtual void OnMove (UIPanel panel) { WrapContent(); }     void WrapContent() {        Vector3[] corners = mPanel.worldCorners;         for (int i = 0; i < 4; ++i) {            Vector3 v = corners[i];            v = mTrans.InverseTransformPoint(v);            corners[i] = v;        }        Vector3 center = Vector3.Lerp(corners[0], corners[2], 0.5f);         if (mHorizontal) {  //横向            for (int i = 0, imax = mChildren.Count; i < imax; ++i) {                Transform t = mChildren[i];                float distance = t.localPosition.x - center.x;                float min = corners[0].x - 100;                float max = corners[2].x + 100;                 distance += mPanel.clipOffset.x - mTrans.localPosition.x;                if (!UICamera.IsPressed(t.gameObject)) {                    NGUITools.SetActive(t.gameObject, (distance > min && distance < max), false);                }            }        } else {            //竖向            for (int i = 0, imax = mChildren.Count; i < imax; ++i) {                Transform t = mChildren[i];                float distance = t.localPosition.y - center.y;                float min = corners[0].y - 100;                float max = corners[2].y + 100;                 distance += mPanel.clipOffset.y - mTrans.localPosition.y;                if (!UICamera.IsPressed(t.gameObject)) {                    bool active = t.gameObject.activeSelf;                    bool willactive = distance > min && distance < max;                    if (active == willactive) continue;                    NGUITools.SetActive(t.gameObject, willactive, false);                }            }        }    }}