学步园

<fx:Style>
  @namespace mx "library://ns.adobe.com/flex/mx";
  
  mx|ToolTip {
   fontFamily: "Arial";
   fontSize: 16;
   fontWeight: "bold";
   color: #FF0000;
   backgroundColor: #FFCCCC;
  }
 </fx:Style>

protected function powerLayer_graphicAddHandler(event:GraphicEvent):void
   {
    // TODO Auto-generated method stub
    event.graphic.toolTip = event.graphic.attributes.一级类名称 + "\n";
   }

<esri:FeatureLayer outFields="[一级类名称]" graphicAdd="powerLayer_graphicAddHandler(event)" id="powerLayer"  />