Flex中怎么给表格中的滚动条定位避免刷新回到原

<?xml version="1.0" encoding="utf-8"?> 
<s:Application xmlns:fx="http://ns.adobe./mxml/2009" 
xmlns:s="library://ns.adobe./flex/spark" 
xmlns:mx="library://ns.adobe./flex/mx" 
creationComplete="initHandler(event)" 
width="100%" height="100%"> 
<s:layout> 
<s:BasicLayout/> 
</s:layout> 
<fx:Script> 
<![CDATA[ 
import mx.collections.ArrayCollection; 
import mx.controls.Alert; 
import mx.events.FlexEvent; 

[Bindable] 
//表格数据绑定 
private var gridArray:ArrayCollection = new ArrayCollection([ 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"}, 
{Jan:"5678",Feb:"7890",Mar:"3454",Apr:"4565",May:"6756",Jun:"5656",Jul:"7867",Aug:"8990",Sep:"5676",Oct:"4655",Nov:"6778",Dec:"8909", 
Jan1:"3344",Feb1:"5676",Mar1:"7898",Apr1:"9089",May1:"9009",Jun1:"5675",Jul1:"3433",Aug1:"4455",Sep1:"6676",Oct1:"7867",Nov1:"4556",Dec1:"8656"} 
]); 

/ 
 初始化函数 
/ 
protected function initHandler(event:FlexEvent):void 
{ 

} 

/ 
 刷新按钮函数 
/ 
protected function refresh_clickHandler(event:MouseEvent):void 
{ 
var hx:Object = hsb.left; 
var hy:Number = hsb.y; 

//var dx:Number = dataGrid.contentMouseX; 
//var dy:Number = dataGrid.contentMouseY; 
//Alert.show("hx"+hx+"\n"+"hy: "+hy + "\n" + "dx: " + dx + "\n" + "dy: " + dy); 
Alert.show("hx"+hx+"\n"+"hy: "+hy); 
} 

]]> 
</fx:Script> 
<fx:Declarations> 
<!-- 将非可视元素（例如服务、值对象）放在此处 --> 
</fx:Declarations> 

<mx:VBox width="100%" height="100%" paddingBottom="10" paddingLeft="10" paddingRight="20" 
paddingTop="10" horizontalAlign="center"> 
<mx:HBox width="100%" height="30"> 
<s:Label width="100%"/> 
<s:Button id="refresh" label="刷新" click="refresh_clickHandler(event)"/> 
</mx:HBox> 
<mx:DataGrid width="1350" height="90%" id="dataGrid" dataProvider="{gridArray}" horizontalScrollPolicy="on" textAlign="center"> 
<mx:columns> 
<mx:DataGridColumn headerText="2013年01月" dataField="Jan" width="200"/> 
<mx:DataGridColumn headerText="2013年02月" dataField="Feb" width="200"/> 
<mx:DataGridColumn headerText="2013年03月" dataField="Mar" width="200"/> 
<mx:DataGridColumn headerText="2013年04月" dataField="Apr" width="200"/> 
<mx:DataGridColumn headerText="2013年05月" dataField="May" width="200"/> 
<mx:DataGridColumn headerText="2013年06月" dataField="Jun" width="200"/> 
<mx:DataGridColumn headerText="2013年07月" dataField="Jul" width="200"/> 
<mx:DataGridColumn headerText="2013年08月" dataField="Aug" width="200"/> 
<mx:DataGridColumn headerText="2013年09月" dataField="Sep" width="200"/> 
<mx:DataGridColumn headerText="2013年10月" dataField="Oct" width="200"/> 
<mx:DataGridColumn headerText="2013年11月" dataField="Nov" width="200"/> 
<mx:DataGridColumn headerText="2013年12月" dataField="Dec" width="200"/> 
<mx:DataGridColumn headerText="2014年01月" dataField="Jan1" width="200"/> 
<mx:DataGridColumn headerText="2014年02月" dataField="Feb1" width="200"/> 
<mx:DataGridColumn headerText="2014年03月" dataField="Mar1" width="200"/> 
<mx:DataGridColumn headerText="2014年04月" dataField="Apr1" width="200"/> 
<mx:DataGridColumn headerText="2014年05月" dataField="May1" width="200"/> 
<mx:DataGridColumn headerText="2014年06月" dataField="Jun1" width="200"/> 
<mx:DataGridColumn headerText="2014年07月" dataField="Jul1" width="200"/> 
<mx:DataGridColumn headerText="2014年08月" dataField="Aug1" width="200"/> 
<mx:DataGridColumn headerText="2014年09月" dataField="Sep1" width="200"/> 
<mx:DataGridColumn headerText="2014年10月" dataField="Oct1" width="200"/> 
<mx:DataGridColumn headerText="2014年11月" dataField="Nov1" width="200"/> 
<mx:DataGridColumn headerText="2014年12月" dataField="Dec1" width="200"/> 
</mx:columns> 
</mx:DataGrid> 
<!-- 
<s:HScrollBar id="hsb" width="100%" viewport="{dataGrid}"/> 
--> 

<s:HScrollBar id="hsb" width="100%"/> 

</mx:VBox> 
</s:Application>