invalidateList and validateNow

    

    调用DataGrid的InvalidateList和validateNow两个方法来实现动态的刷新视图。如果你使用了数据源绑定操作的话一般来说DataGrid会自动的帮你去更新视图，具体的应该也会去调用这两个方法。所以遇到DataGrid视图方面的问题可以通过这两个方法来试试。

    invalidateList()这个函数用来刷新 DataGrid 的每一行，validateNow()这个是在 DataGrid 的属性（大小，位置等）改变时，进行手动刷新的。我们要刷新纪录，就要用 invalidateList() 。

    for <s:DataGrid/>  ,没有invalidateList()，用invalidateTypicalItem()取而代之；

1、invalidateList例子

<?xml version="1.0" encoding="utf-8"?><s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"    xmlns:s="library://ns.adobe.com/flex/spark"    xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"><fx:Declarations><!-- 将非可视元素（例如服务、值对象）放在此处 --></fx:Declarations><s:layout><s:HorizontalLayout/></s:layout><fx:Script><![CDATA[import mx.collections.ArrayCollection;//绑定表格用的数据[Bindable]private var arr1:ArrayCollection = new ArrayCollection([{neName:"教工路文一路路口相机_4", neType:"相机" , neAlarmType:"设备告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"2级"},{neName:"学院路文一路路口相机_3", neType:"相机" , neAlarmType:"环境告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"3级"},{neName:"文一路莫干山路路口相机_1", neType:"相机" , neAlarmType:"连接通信告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"1级"},{neName:"文一路莫干山路路口相机_3", neType:"相机" ,  neAlarmType:"性能告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"4级"}]);[Bindable]private var arr2:ArrayCollection = new ArrayCollection([{neName:"教工路文一路路口相机_4", neType:"相机" , neAlarmType:"设备告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"2级"},{neName:"学院路文一路路口相机_3", neType:"相机" , neAlarmType:"环境告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"3级"},{neName:"文一路莫干山路路口相机_1", neType:"相机" , neAlarmType:"连接通信告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"1级"},{neName:"文一路莫干山路路口相机_3", neType:"相机" ,  neAlarmType:"性能告警" , removeStatus:"未清除" , confirmStatus:"未确认" , neAlarmGrade:"4级"}]);//删除告警信息public function deleteAlarmRecord1():void{arr1.removeItemAt(alarmGrid1.selectedIndex);}//确认告警信息public function confirmAlarmInfo1():void{arr1.getItemAt(alarmGrid1.selectedIndex).confirmStatus = "已确认";alarmGrid1.invalidateTypicalItem();}//删除告警信息public function deleteAlarmRecord2():void{arr2.removeItemAt(alarmGrid2.selectedIndex);}//确认告警信息public function confirmAlarmInfo2():void{arr2.getItemAt(alarmGrid2.selectedIndex).confirmStatus = "已确认";alarmGrid2.invalidateList();}]]></fx:Script><s:DataGrid id="alarmGrid1" width="600" height="285" requestedRowCount="4" dataProvider="{arr1}"><s:columns><s:ArrayList><s:GridColumn dataField="neName" headerText="名称"></s:GridColumn><s:GridColumn dataField="neType" headerText="类型"></s:GridColumn><s:GridColumn dataField="removeStatus" headerText="清除状态"></s:GridColumn><s:GridColumn dataField="confirmStatus" headerText="确认状态"></s:GridColumn><s:GridColumn headerText="操作"><s:itemRenderer><fx:Component><s:GridItemRenderer><s:HGroup> <mx:LinkButton toolTip="清除" label="清除" click="outerDocument.deleteAlarmRecord1();" textDecoration="underline" color="#2066CF" fontWeight="normal"/> <mx:LinkButton toolTip="确认" label="确认" click="outerDocument.confirmAlarmInfo1()" textDecoration="underline" color="#2066CF" fontWeight="normal"/> </s:HGroup></s:GridItemRenderer></fx:Component></s:itemRenderer></s:GridColumn></s:ArrayList></s:columns></s:DataGrid><mx:DataGrid id="alarmGrid2" width="600" height="285" dataProvider="{arr2}"><mx:columns><mx:DataGridColumn dataField="neName" headerText="名称"/><mx:DataGridColumn dataField="neType" headerText="类型"/><mx:DataGridColumn dataField="removeStatus" headerText="清除状态"/><mx:DataGridColumn dataField="confirmStatus" headerText="确认状态"/><mx:DataGridColumn headerText="操作"><mx:itemRenderer><fx:Component><mx:HBox><mx:LinkButton toolTip="清除" label="清除" click="outerDocument.deleteAlarmRecord2();" textDecoration="underline" color="#2066CF" fontWeight="normal"/> <mx:LinkButton toolTip="确认" label="确认" click="outerDocument.confirmAlarmInfo2()" textDecoration="underline" color="#2066CF" fontWeight="normal"/> </mx:HBox></fx:Component></mx:itemRenderer></mx:DataGridColumn></mx:columns></mx:DataGrid></s:Application>

2、

dataGrid1.scroller.verticalScrollBar.value = dataGrid1.scroller.verticalScrollBar.maximum;

dataGrid2.verticalScrollPosition = dataGrid2.maxVerticalScrollPosition;

<?xml version="1.0" encoding="utf-8"?><s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"    xmlns:s="library://ns.adobe.com/flex/spark"    xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"   creationComplete="init()"><fx:Declarations><!-- 将非可视元素（例如服务、值对象）放在此处 --><s:ArrayCollection id="arrColl1" collectionChange="arrColl_collectionChange1(event);" /><s:ArrayCollection id="arrColl2" collectionChange="arrColl_collectionChange2(event);" /></fx:Declarations><s:layout><s:HorizontalLayout/></s:layout><fx:Script><![CDATA[import mx.events.CollectionEvent;private var timer:Timer;private function init():void {timer = new Timer(500);timer.addEventListener(TimerEvent.TIMER, onTimer);timer.start();}private function onTimer(evt:TimerEvent):void {var now:String = new Date().toString();arrColl1.addItem({id:timer.currentCount, time:now});arrColl2.addItem({id:timer.currentCount, time:now});}private function arrColl_collectionChange1(evt:CollectionEvent):void {callLater(autoScrollDataGrid1);}private function arrColl_collectionChange2(evt:CollectionEvent):void {callLater(autoScrollDataGrid2);}private function autoScrollDataGrid1():void {if (dataGrid1) {dataGrid1.validateNow();dataGrid1.scroller.verticalScrollBar.value = dataGrid1.scroller.verticalScrollBar.maximum;}}private function autoScrollDataGrid2():void {if (dataGrid2) {dataGrid2.validateNow();dataGrid2.verticalScrollPosition = dataGrid2.maxVerticalScrollPosition;}}]]></fx:Script><s:DataGrid id="dataGrid1" dataProvider="{arrColl1}" verticalScrollPolicy="on" width="200" requestedRowCount="15" ><s:columns><s:ArrayList><s:GridColumn dataField="id" width="50"/><s:GridColumn dataField="time"/></s:ArrayList></s:columns></s:DataGrid><mx:DataGrid id="dataGrid2"dataProvider="{arrColl2}"verticalScrollPolicy="on"width="200" rowCount="8"><mx:columns><mx:DataGridColumn dataField="id" width="50" /><mx:DataGridColumn dataField="time" /></mx:columns></mx:DataGrid></s:Application>