Flex组合框子(textInput, button)访问

Question

我需要在不创建自定义组件的情况下访问组合框子组件(textinput和button)。我知道最佳实践是创建自定义组件，但仍然需要访问组合框子组件(如textinput)并侦听它们的事件。有什么帮助吗?

Answer 1

你可以像这样给你的comboBox的textInput添加一个事件:

myComboBox.textInput.addEventListener(TextOperationEvent.CHANGE, myFunction);

因为textInput对象是comboBox对象(myComboBox.textInput)的子对象。

---

下面是一个完整的工作示例

<?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" creationComplete="creationCompleteHandler(event)">
    <fx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.events.FlexEvent;
            import spark.events.IndexChangeEvent;
            import spark.events.TextOperationEvent;
            [Bindable]
            private var _dp:ArrayCollection = new ArrayCollection([
                {id : "1", name : "Paul"},
                {id : "2", name : "Andrew"},
                {id : "2", name : "Bob"}
            ]);
            protected function creationCompleteHandler(event:FlexEvent):void
            {
                myComboBox.textInput.addEventListener(TextOperationEvent.CHANGE, showTextInputValue);
                myComboBox.addEventListener(IndexChangeEvent.CHANGE, showComboValue);
            }
            protected function showTextInputValue(event:TextOperationEvent):void
            {
                textFieldValue.text = "myComboBox.textInput : " + event.currentTarget.text;
            }
            protected function showComboValue(event:IndexChangeEvent):void
            {
                if (event.newIndex > -1)
                    comboBoxValue.text = "myComboBox selected item is : " + myComboBox.selectedItem.name;
            }
        ]]>
    </fx:Script>
    <s:layout>
        <s:VerticalLayout/>
    </s:layout>
    <s:ComboBox id="myComboBox" labelField="name" dataProvider="{_dp}"/>
    <mx:Spacer height="100"/>
    <s:Label id="textFieldValue"/>
    <s:Label id="comboBoxValue"/>
</s:WindowedApplication>

Answer 2

你可以为Event.ADDED添加一个事件监听器到ComboBox，并检查event.target的类型以pin point所需的显示对象(例如if (event.target is TextField ) doStuff();)。你将无法访问ComboBox的属性(以替换文本字段或按钮与不同的)，但你可以修改添加到舞台的实例