Flex 4 设置ToolTip样式

通过设置CSS样式可以设置ToolTip的样式：
<fx:Style>
@namespace s "library://ns.adobe.com/flex/spark";
@namespace mx "library://ns.adobe.com/flex/mx";
mx|ToolTip {
backgroundColor: black;
backgroundAlpha: 1.0;
cornerRadius: 0;
color: white;
fontSize: 12;
}
</fx:Style>

一个自定义ToolTip中显示自定义图片的例子:
Application中
<?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>
<fx:Script>
<![CDATA[
import mx.controls.ToolTip;
import mx.events.ToolTipEvent;
import mx.managers.ToolTipManager;
private function createToolTips(event:ToolTipEvent):void {
var tip:MyToolTips=new MyToolTips();
tip.str="我的SuperToolTIp";
tip.str1="img/01.gif";
event.toolTip = tip;
}
private function showToolTips(evt:ToolTipEvent):void{
evt.toolTip.x=a.x + a.width + 10;
evt.toolTip.y=a.y;
}
]]>
</fx:Script>
<mx:HBox height="100%" verticalAlign="middle" width="100%" horizontalAlign="center">
<mx:Button id="a"
label="SuperToolTip"
width="100"
toolTip="00000"
toolTipCreate="createToolTips(event);"
toolTipShow="showToolTips(event);"/>
</mx:HBox>
</s:Application>
自定义ToolTip
MyToolTips.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
implements="mx.core.IToolTip"
xmlns:mx="library://ns.adobe.com/flex/mx"
backgroundColor="#00ff33" alpha=".8" width="100%" borderStyle="solid" cornerRadius="7">
<fx:Script>
<![CDATA[
import mx.core.IToolTip;
public var str:String="";
public var str1:String="";
public var _text:String;
public function get text():String {
return _text;
}
public function set text(value:String):void {
}
]]>
</fx:Script>
<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
</fx:Declarations>
<mx:VBox width="100%" height="100%">
<mx:Image source="{str1}"/>
<mx:Text text="{this.str}" color="#000000" fontSize="13"/>
</mx:VBox>
</mx:Canvas>