取类名：传进一个object，返回类的全名

varloader:URLLoader=newURLLoader();

varclassName:String=getQualifiedClassName(loader);

trace(className);//Displaysflash.net.URLLoader

取父类的类名：传进一个object，返回父类的类名

varloader:URLLoader=newURLLoader();

varclassName:String=getQualifiedSuperclassName(loader);

trace(className);//Displaysflash.events.EventDispatcher

根据类名取类

varclassReference:Class=Class(getDefinitionByName("flash.net.URLLoader"));

//一但你得到了类的引用后，就可以这样

varinstance:Object=newclassReference();

getQualifiedClassName()或getQualifiedSuperclassName()与getDefinitionByName()结合使用的例子：

varloader:URLLoader=newURLLoader();

varclassName:String=getQualifiedClassName(loader);

varclassReference:Class=Class(getDefinitionByName(className));

varinstance:Object=newclassReference();

Introspection：describeType()返回对象的类型描述

例如：

varloader:URLLoader=newURLLoader();

vardescription:XML=describeType(loader);

trace(description);

输出:

<typename="flash.net::URLLoader"base="flash.events::EventDispatcher"

isDynamic="false"isFinal="false"isStatic="false">

<metadataname="Event">

<argkey="name"value="httpStatus"/>

<argkey="type"value="flash.events.HTTPStatusEvent"/>

</metadata>

<metadataname="Event">

<argkey="name"value="securityError"/>

<argkey="type"value="flash.events.SecurityErrorEvent"/>

</metadata>

<metadataname="Event">

<argkey="name"value="ioError"/>

<argkey="type"value="flash.events.IOErrorEvent"/>

</metadata>

<metadataname="Event">

<argkey="name"value="progress"/>

<argkey="type"value="flash.events.ProgressEvent"/>

</metadata>

<metadataname="Event">

<argkey="name"value="complete"/>

<argkey="type"value="flash.events.Event"/>

</metadata>

<metadataname="Event">

<argkey="name"value="open"/>

<argkey="type"value="flash.events.Event"/>

</metadata>

<extendsClasstype="flash.events::EventDispatcher"/>

<extendsClasstype="Object"/>

<implementsInterfacetype="flash.events::IEventDispatcher"/>

<constructor>

<parameterindex="1"type="flash.net::URLRequest"optional="true"/>

</constructor>

<variablename="bytesTotal"type="uint"/>

<variablename="data"type="*"/>

<methodname="load"declaredBy="flash.net::URLLoader"returnType="void">

<parameterindex="1"type="flash.net::URLRequest"optional="false"/>

</method>

<methodname="close"declaredBy="flash.net::URLLoader"returnType="void"/>

<variablename="dataFormat"type="String"/>

<variablename="bytesLoaded"type="uint"/>

<methodname="dispatchEvent"declaredBy="flash.events::EventDispatcher"

returnType="Boolean">

<parameterindex="1"type="flash.events::Event"optional="false"/>

</method>

<methodname="toString"declaredBy="flash.events::EventDispatcher"

returnType="String"/>