说一个关于unity3d uiwrapcontent的列子，有源代码，供大家参考学习，这个也是NGUI 3.5.5中加入的UIWrapContent，它会将不显示的Scroll Item设为disabled，这样就使得每帧更新的Scroll Item减少到当前显示的那几个，就再也不会出现掉帧的情况了。

不过UIWrapContent只能创建循环的Scroll View，不过只需要简单的几处修改，就能实现在普通的Scroll View上。

复制一份UIWrapContent.cs，重命名为UIBetterGrid.cs，修改类名

1. // line: 19 - 20, file: UIWrapContent.cs
2. [AddComponentMenu("NGUI/Interaction/Wrap Content")]
3. public class UIWrapContent : MonoBehaviour
4. 
   
5. 
   
6. 修改后的代码如下：
7. 
   
8. // line: 19 - 20, file: UIBetterGrid.cs
9. [AddComponentMenu("NGUI/Interaction/Better Grid")]
10. public class UIBetterGrid : MonoBehaviour
11. 
    
12. 
    
13. 修改初始化代码
14. 
    
15. // line: 52 - 54, file: UIWrapContent.cs
16. mScroll.restrictWithinPanel = false;
17. if (mScroll.dragEffect == UIScrollView.DragEffect.MomentumAndSpring)
18. mScroll.dragEffect = UIScrollView.DragEffect.Momentum;
19. 
    
20. 
    
21. 修改后的代码如下：
22. 
    
23. // line: 52 - 54, file: UIBetterGrid.cs
24. mScroll.restrictWithinPanel = true;
25. //if (mScroll.dragEffect == UIScrollView.DragEffect.MomentumAndSpring)
26. //mScroll.dragEffect = UIScrollView.DragEffect.Momentum;
27. 
    
28. 
    
29. 注释创建首尾循环的代码
30. 
    
31. // line 159 - 170, file: UIBetterGrid.cs 
32. //if (distance < -extents)
33. //{
34. //t.localPosition += new Vector3(extents * 2f, 0f, 0f);
35. //distance = t.localPosition.x - center.x;
36. //UpdateItem(t, i);
37. //}
38. //else if (distance > extents)
39. //{
40. //t.localPosition -= new Vector3(extents * 2f, 0f, 0f);
41. //distance = t.localPosition.x - center.x;
42. //UpdateItem(t, i);
43. //}
44. 
    
45. // line 190 - 201, file: UIBetterGrid.cs
46. //if (distance < -extents)
47. //{
48. //t.localPosition += new Vector3(0f, extents * 2f, 0f);
49. //distance = t.localPosition.y - center.y;
50. //UpdateItem(t, i);
51. //}
52. //else if (distance > extents)
53. //{
54. //t.localPosition -= new Vector3(0f, extents * 2f, 0f);
55. //distance = t.localPosition.y - center.y;
56. //UpdateItem(t, i);
57. //}
58. 
    
59. 
    
60. 修改UIScrollView.cs
61. 
    
62. // line 173, file: UIWrapContent.cs
63. mBounds = NGUIMath.CalculateRelativeWidgetBounds(mTrans, mTrans);  
64. 
    
65. 
    
66. 修改后的代码如下：
67. 
    
68. // line 173, file: UIBetterGrid.cs
69. mBounds = NGUIMath.CalculateRelativeWidgetBounds(mTrans, mTrans,true);