Flex中如何利用folderClosedIcon和folderOpenIcon样式，去掉Tree控件默认文件夹图标

main.mxml

1. <?xml version="1.0" encoding="utf-8"?>
2. <mx:Applicationxmlns:mx="http://www.adobe.com/2006/mxml"
3. layout="vertical"
4. verticalAlign="middle"
5. backgroundColor="white">
7. <mx:XMLid="dp">
8. <mlb>
9. <leaguelabel="American League">
10. <divisionlabel="East">
11. <teamlabel="Boston" />
12. <teamlabel="New York" />
13. <teamlabel="Toronto" />
14. <teamlabel="Baltimore" />
15. <teamlabel="Tampa Bay" />
16. </division>
17. <divisionlabel="Central">
18. <teamlabel="Cleveland" />
19. <teamlabel="Detroit" />
20. <teamlabel="Minnesota" />
21. <teamlabel="Chicago" />
22. <teamlabel="Kansas City" />
23. </division>
24. <divisionlabel="West">
25. <teamlabel="Los Angeles" />
26. <teamlabel="Seattle" />
27. <teamlabel="Oakland" />
28. <teamlabel="Texas" />
29. </division>
30. </league>
31. </mlb>
32. </mx:XML>
34. <mx:Style>
35. Tree {
36. folderClosedIcon: ClassReference(null);
37. folderOpenIcon: ClassReference(null);
38. }
39. </mx:Style>
41. <mx:Treeid="TreeProject"
42. dataProvider="{dp.league}"
43. labelField="@label"
44. iconField="@icon"
45. showRoot="true"
46. width="320"
47. rowCount="9"/>
49. </mx:Application>