State属性的用法（写于开发登录界面时）

<?xml version="1.0" ?>
<!-- Simple example to demonstrate the States class. -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">

 <mx:Script>
  <![CDATA[
   import mx.controls.Alert;
   import flash.events.MouseEvent;
   
   internal function newClick(event:MouseEvent):void
   {
    Alert.show("这是一个新状态!","tips");
   }
  ]]>
 </mx:Script>
    <!-- Define one view state, in addition to the base state.-->
    <mx:states>
        <mx:State name="Register">
            <mx:AddChild relativeTo="{loginForm}" position="lastChild">
                <mx:target>
                    <mx:FormItem id="confirm" label="Confirm:">
                        <mx:TextInput/>
                    </mx:FormItem>
                </mx:target>
            </mx:AddChild>
            <mx:SetProperty target="{loginPanel}" name="title" value="Register"/>
            <mx:SetProperty target="{loginButton}" name="label" value="Register"/>
            <mx:SetStyle target="{loginButton}"
                name="color" value="blue"/>
            <mx:RemoveChild target="{registerLink}"/>
            <mx:AddChild relativeTo="{spacer1}" position="before">
                <mx:target>
                    <mx:LinkButton id="loginLink" label="Return to Login" click="currentState=''"/>
                </mx:target>
            </mx:AddChild>
        </mx:State>
       
        <mx:State name="newstate">
            <mx:SetProperty target="{loginPanel}" name="height" value="287"/>
            <mx:RemoveChild target="{formitem1}"/>
            <mx:AddChild relativeTo="{loginForm}" position="lastChild">
                <mx:FormItem label="输入邮箱：" fontSize="12">
                    <mx:TextInput/>
                </mx:FormItem>
            </mx:AddChild>
            <mx:AddChild relativeTo="{loginForm}" position="lastChild" >
                <mx:FormItem label="Label">
                    <mx:Button label="Button" id="newBtn"/>
                </mx:FormItem>
            </mx:AddChild>
            <mx:SetProperty target="{loginPanel}" name="title" value="newstate"/>
            <mx:SetEventHandler target="{registerLink}" name="click" handler="currentState=''"/>
            <mx:SetEventHandler target="{newBtn}" name="click"  handlerFunction="newClick"/>
             
       
         
        </mx:State>
    </mx:states>

    <!-- Define a Panel container that defines the login form.-->
    <mx:Panel title="Login" id="loginPanel"
        horizontalScrollPolicy="off" verticalScrollPolicy="off"
        paddingTop="10" paddingLeft="10" paddingRight="10" paddingBottom="10">

        <mx:Text width="100%" color="blue"
            text="Click the 'Need to Register?' link to change state. Click the 'Return to Login' link to return to the base state."/>

        <mx:Form id="loginForm" >
            <mx:FormItem label="Username:">
                <mx:TextInput/>
            </mx:FormItem>
            <mx:FormItem label="Password:" id="formitem1">
                <mx:TextInput/>
            </mx:FormItem>
        </mx:Form>
        <mx:ControlBar id="controlbar1">
            <mx:LinkButton id="registerLink"  label="Need to Register?"
                click="currentState='newstate'"/>
            <mx:Spacer width="100%" id="spacer1"/> /*Spacer 控件，使用灵活的 Spacer 控件将 Button 控件推到右侧，以便 Button 控件与 HBox 容器的右边对齐*/
*            <mx:Button label="Login" id="loginButton"/>
        </mx:ControlBar>
    </mx:Panel>
</mx:Application>

////////////////////////////////////////////////////////////////////////////////////////以上为state的使用，规定不同状态，通常与transitition（规定状态切换顺去）一起使用/////////////////////

 

 

 

 

 

 

①在addchild属性中有creationpolicy即“创建策略”，共有4个值：auto  ，all， queued  ，none，分别表示 ： 需要此对象是创建   ；总是创建对象； 对象完成初始化才开始创建子机元素；不创建对象。

 

② /*Spacer 控件，使用灵活的 Spacer 控件将 Button 控件推到右侧，以便 Button 控件与 HBox 容器的右边对齐*/