Flex中如何通过rowCount属性，动态改变DataGrid显示行数

<iframe src="http://blog.minidx.com/ext05/resizing-a-flex-datagrid-control-using-the-rowcount-property/main.html" width="550" height="380"></iframe>

1. <?xml version="1.0" encoding="utf-8"?>
2. <mx:Applicationxmlns:mx="http://www.adobe.com/2006/mxml"
3. layout="vertical"
4. verticalAlign="top"
5. backgroundColor="white">
7. <mx:Arrayid="arr">
8. <mx:Objectcol1="1" col2="A" col3="a" />
9. <mx:Objectcol1="2" col2="B" col3="b" />
10. <mx:Objectcol1="3" col2="C" col3="c" />
11. <mx:Objectcol1="4" col2="D" col3="d" />
12. <mx:Objectcol1="5" col2="E" col3="e" />
13. <mx:Objectcol1="6" col2="F" col3="f" />
14. </mx:Array>
16. <mx:ApplicationControlBardock="true">
17. <mx:Form>
18. <mx:FormItemlabel="rowCount:">
19. <mx:HSliderid="slider"
20. minimum="0"
21. maximum="{arr.length+1}"
22. value="4"
23. liveDragging="true"
24. snapInterval="1"
25. tickInterval="1"
26. dataTipPrecision="0"/>
27. </mx:FormItem>
28. </mx:Form>
29. </mx:ApplicationControlBar>
31. <mx:DataGridid="dataGrid"
32. dataProvider="{arr}"
33. rowCount="{slider.value}"/>
35. </mx:Application>