In flex 3, use the tag mx:itemRenderer
:
<mx:DataGrid id="myDataGrid" dataProvider="{myDP}">
<mx:columns>
<mx:DataGridColumn dataField="field">
<mx:itemRenderer>
<mx:Component>
<mx:Button label="{data.field}"/>
</mx:Component>
</mx:itemRenderer>
</mx:DataGridColumn>
</mx:columns>
</mx:DataGrid>
In flex 4, use spark dataGrid and the s:itemRenderer
tag:
<s:DataGrid dataProvider="{myDP}">
<s:columns>
<s:ArrayList>
<s:GridColumn dataField="Price">
<s:itemRenderer>
<fx:Component>
<s:GridItemRenderer>
<s:Button label="{data.Price}"/>
</s:GridItemRenderer>
</fx:Component>
</s:itemRenderer>
</s:GridColumn>
</s:ArrayList>
</s:columns>
</s:DataGrid>