Flex DataGrid数字排序

支持把字符类型的数据按数字排列，同时固定住某些特殊行在底端（比如合计行）。

 <?xml version="1.0" encoding="utf-8"?><mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"><mx:Script><!--[CDATA[import mx.controls.dataGridClasses.DataGridColumn;import mx.utils.ObjectUtil;private function getSortFun(field:DataGridColumn,keyField:String="@col1",keyValue:String="1"):Function{return function(o1:Object,o2:Object):int{if(o1[keyField] == keyValue) {return field.sortDescending ? -1 : 1;} else if(o2[keyField] == keyValue) {return field.sortDescending ? 1 : -1;}return ObjectUtil.numericCompare(new Number(o1[field.dataField]),new Number(o2[field.dataField]));};}]]--></mx:Script><mx:XMLList xmlns="" id="data"><node col1="1" col2="1" col3="合计"/><node col1="11" col2="1" col3="a1"/><node col1="91" col2="1" col3="a1"/><node col1="100" col2="1" col3="a1"/><node col1="1012" col2="1" col3="a1"/><node col1="12123" col2="1" col3="a1"/><node col1="91" col2="1" col3="a1"/><node col1="9" col2="1" col3="a1"/></mx:XMLList><mx:DataGrid width="100%" height="100%" dataProvider="{data}"><mx:columns><mx:DataGridColumn headerText="Column 3" dataField="@col3"/><mx:DataGridColumn headerText="Column 1" id="col1" dataField="@col1" sortCompareFunction="getSortFun(col1)"/><mx:DataGridColumn headerText="Column 2" dataField="@col2"/></mx:columns></mx:DataGrid></mx:Application>