flex使用样式控制button的icon（图片）切换
1.定义button
<s:Button styleName="myButton2" width="92" height="29" />?
2.设置样式
?
.myButton2:up{icon:Embed("assets/pic/title/login-default.png");}.myButton2:over,.myButton2:down{icon:Embed("assets/pic/loginButtonTwo.png");}??