The target can also be set once the Effect has been instantiated by using the target property of the Effect class. The target is the UIComponent that the Effect will affect when the play method of the Effect is called. When an Effect is defined in MXML, the target UIComponent must be assigned within a binding tag: 目標的設置也可以在Effect 實例化完成后通過設置Effect 類的target 屬性來完成。所謂目標就是一個當調用Effect 的play 方法的時候會對其產生作用的UIComponent。當一個Effect定義在MXML 后，目標UIComponent 必須以綁定標簽的形式進行分配：
