Flex动态生成DataGrid 动态生成列。

<s:DataGrid id="grid" width="100%" height="100%" requestedRowCount="4">
		<!--<s:columns>
			<s:ArrayList>
				<s:GridColumn dataField="dataField1" headerText="Column 1"></s:GridColumn>
				<s:GridColumn dataField="dataField2" headerText="Column 2"></s:GridColumn>
				<s:GridColumn dataField="dataField3" headerText="Column 3"></s:GridColumn>
				<s:GridColumn dataField="dataField4" headerText="Column 4" itemRenderer="com.view.renderers.DataGridRenderer"></s:GridColumn>
			</s:ArrayList>
		</s:columns>-->
		<s:typicalItem>
			<fx:Object dataField1="Sample Data" dataField2="Sample Data" dataField3="Sample Data" dataField4 = "woqunimabideao"></fx:Object>
		</s:typicalItem>
		<s:ArrayList>
			<fx:Object dataField1="data1" dataField2="a" dataField3="e" dataField4="1"></fx:Object>
			<fx:Object dataField1="data2" dataField2="b" dataField3="f" dataField4="2"></fx:Object>
			<fx:Object dataField1="data3" dataField2="c" dataField3="g" dataField4="3"></fx:Object>
			<fx:Object dataField1="data4" dataField2="d" dataField3="h" dataField4="4"></fx:Object>
		</s:ArrayList>
	</s:DataGrid>

 如何动态生成？

var cols:ArrayList = new ArrayList();
					var gridColumn:GridColumn = new GridColumn();
					gridColumn.dataField = "操作";
					gridColumn.headerText = "Column 1";
					
					gridColumn.itemRenderer = new ClassFactory(DataGridRenderer);
					cols.addItem(gridColumn);
					grid.columns = cols;