Flex4 CSS 以及namespace使用

Flex4的css文件中有3种常见的style声明类型:
如下实例代码：

@namespace "library://ns.adobe.com/flex/mx";
@namespace namespaceName "com.window.*";

ComponentClassName {

}

namespaceName |ComponentClassName{

}

.styleName {

}

在as、mxml代码中有4 种方法获取style声明或设置组建style：
1.  FlexGlobals.topLevelApplication.styleManager.getStyleDeclaration("com.window.ComponentClassName");
2.  FlexGlobals.topLevelApplication.styleManager.getStyleDeclaration(".styleName ");
3.  FlexGlobals.topLevelApplication.styleManager.getStyleDeclaration("ComponentClassName");
4.  This. StyleName = styleName

注意在Flex4中，当调用FlexGlobals.topLevelApplication.styleManager.getStyleDeclaration时，如果调用的类不在自定义style声明中，必须指定全局包名，而不是单个class名。

示例代码如下：

<?xml version="1.0"?>
 <!-- migration/StyleManagerExample.mxml --> 
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:mx="library://ns.adobe.com/flex/mx" xmlns:s="library://ns.adobe.com/flex/spark" 
creationComplete="initApp()">
 <fx:Script>
<![CDATA[
 public function initApp():void { 

/* New method of accessing the StyleManager. */
styleManager.getStyleDeclaration("spark.components.Button").setStyle("fontSize",15); 

/* Old method; no longer works. */
StyleManager.getStyleDeclaration("Button").setStyle(setStyle("fontSize",15); 
} 
]]>
</fx:Script> 
<s:Button id="myButton" label="Click Me"/> 
</s:Application>