设置ComboBox控件的提示内容.

最新推荐文章于 2025-05-24 09:28:34 发布

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最新推荐文章于 2025-05-24 09:28:34 发布

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本文介绍了一个使用Flex框架创建ComboBox控件的例子，并展示了如何设置提示文本(prompt)以指导用户选择。示例中包含了两种实现方式：一种是直接在MXML文件中设置，另一种是在ActionScript中初始化。

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ComboBox控件的prompt属性.
示例：

代码：

" />

</mx:Application>

通过as来实现：

<?xml version="1.0" encoding="utf-8"?>

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white"
        initialize="init();">

    <mx:Script>
        <![CDATA[
            import mx.controls.ComboBox;
            import mx.controls.Button;
            import mx.containers.ApplicationControlBar;

            private var arr:Array;
            private var appControlBar:ApplicationControlBar;
            private var button:Button;
            private var comboBox:ComboBox;

            private function init():void {
                arr = [];
                arr.push({abbrev:"AL", name:"Alabama"});
                arr.push({abbrev:"AK", name:"Alaska"});
                arr.push({abbrev:"AZ", name:"Arizona"});
                arr.push({abbrev:"AR", name:"Arkansas"});
                arr.push({abbrev:"CA", name:"California"});
                arr.push({abbrev:"CO", name:"Colorado"});
                arr.push({abbrev:"CT", name:"Connecticut"});

                button = new Button();
                button.label = "Reset ComboBox";
                button.addEventListener(MouseEvent.CLICK, button_click);

                appControlBar = new ApplicationControlBar();
                appControlBar.dock = true;
                appControlBar.addChild(button);
                Application.application.addChildAt(appControlBar, 0);

                comboBox = new ComboBox();
                comboBox.dataProvider = arr;
                comboBox.labelField = "name";
                comboBox.prompt = "Please select a state

";
                addChild(comboBox);
            }

            private function button_click(evt:MouseEvent):void {
                comboBox.selectedIndex = -1;
            }
        ]]>
    </mx:Script>

</mx:Application>