Flex 4：状态变化事件

Question

我可以使用Flex 4中的任何事件来检测状态变化吗？

Answer 1

我知道这个问题已经过时但是通过谷歌搜索状态变化事件我仍然会到这里，所以想要知道的人：

有一个由组件调度的StateChangeEvent.CURRENT_STATE_CHANGE事件，因此您的应用程序也可以监听它。

在侦听器函数中，您可以访问StateChangeEvent.oldState和StateChangeEvent.newState属性。

Answer 2

如果您正在讨论视图状态，答案是肯定的，您可以像这样监听enterState事件（抱歉示例的简单性，它是我正在处理的项目的一部分，我删除了代码的任何相关部分） ：

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
           xmlns:s="library://ns.adobe.com/flex/spark" 
           xmlns:mx="library://ns.adobe.com/flex/mx"
           minWidth="800" minHeight="600"
           currentState="loading">

<fx:Script>
    <![CDATA[
        import mx.controls.Alert;

        private function onEnterLoadingState():void{
            Alert.show("Enter the loading state.", "Application");
        }

        private function onEnterLoginState():void{
            Alert.show("Enter the login state.", "Application");
        }

        private function onEnterAddState():void{
            Alert.show("Enter the addUser state.", "Application");
        }

        private function changeState(state:String):void{
            currentState = state;
        }
    ]]>
</fx:Script>

<s:states>
    <s:State name="loading" enterState="onEnterLoadingState()"/>
    <s:State name="login" enterState="onEnterLoginState()"/>
    <s:State name="addUser" enterState="onEnterAddState()"/>
</s:states>

<s:Panel id="loadView" includeIn="loading" title="Loading">
    <s:Button label="Go to login" click="changeState('login')"/>
</s:Panel>
<s:Panel id="loginView" includeIn="login" title="Login">
    <s:Button label="Go to addUser" click="changeState('addUser')"/>
</s:Panel>
<s:Panel id="addView" includeIn="addUser" title="AddUser">
    <s:Button label="Return to loading" click="changeState('loading')"/>
</s:Panel>
</s:Application>

如果需要，还有一个exitState事件。 我希望这可以帮助你。

Answer 3

您可以在任何UIComponent类上侦听多个状态事件：

• FlexEvent.STATE_CHANGE_COMPLETE
• FlexEvent.STATE_CHANGE_INTERRUPTED
• StateChangeEvent.CURRENT_STATE_CHANGING
• StateChangeEvent.CURRENT_STATE_CHANGE
• FlexEvent.ENTER_STATE
• FlexEvent.EXIT_STATE

MXML：

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
                       xmlns:s="library://ns.adobe.com/flex/spark" 
                       xmlns:mx="library://ns.adobe.com/flex/mx"

                       enterState="windowedapplication1_enterStateHandler(event)"
                       exitState="windowedapplication1_exitStateHandler(event)"
                       currentStateChange="windowedapplication1_currentStateChangeHandler(event)"
                       currentStateChanging="windowedapplication1_currentStateChangingHandler(event)"
                       stateChangeInterrupted="windowedapplication1_stateChangeInterruptedHandler(event)"
                       stateChangeComplete="windowedapplication1_stateChangeCompleteHandler(event)">

    <fx:Script>
        <![CDATA[
            import mx.events.FlexEvent;


            protected function windowedapplication1_stateChangeCompleteHandler(event:FlexEvent):void
            {

            }

            protected function windowedapplication1_stateChangeInterruptedHandler(event:FlexEvent):void
            {

            }

            protected function windowedapplication1_currentStateChangeHandler(event:StateChangeEvent):void
            {
                var oldState:String = event.oldState;
                var newState:String = event.newState;
            }

            protected function windowedapplication1_currentStateChangingHandler(event:StateChangeEvent):void
            {
                var oldState:String = event.oldState;
                var newState:String = event.newState;
            }

            protected function windowedapplication1_enterStateHandler(event:FlexEvent):void
            {

            }

            protected function windowedapplication1_exitStateHandler(event:FlexEvent):void
            {

            }
        ]]>
    </fx:Script>
</s:WindowedApplication>