设置NumericStepper控件某一边框的宽度。

设置NumericStepper控件，上下左右，某一个边框的宽度.通过borderStyle 和 borderSides 样式。
示例：

代码：

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/05/27/setting-a-border-on-specific-sides-of-a-numericstepper-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            private function checkBox_change(evt:Event):void {
                var sidesStr:String;
                var sidesArr:Array = [];
                if (leftCheckBox.selected) {
                    sidesArr.push("left");
                }
                if (rightCheckBox.selected) {
                    sidesArr.push("right");
                }
                if (topCheckBox.selected) {
                    sidesArr.push("top");
                }
                if (bottomCheckBox.selected) {
                    sidesArr.push("bottom");
                }
                sidesStr = sidesArr.join(" ");
                numericStepper.setStyle("borderSides", sidesStr);
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="border left:">
                <mx:CheckBox id="leftCheckBox"
                        selected="true"
                        change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="border right:">
                <mx:CheckBox id="rightCheckBox"
                        selected="true"
                        change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="border top:">
                <mx:CheckBox id="topCheckBox"
                        selected="true"
                        change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="border bottom:">
                <mx:CheckBox id="bottomCheckBox"
                        selected="true"
                        change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="borderThickness:">
                <mx:HSlider id="slider"
                        minimum="0"
                        maximum="10"
                        value="4"
                        snapInterval="1"
                        tickInterval="1"
                        liveDragging="true" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:NumericStepper id="numericStepper"
            borderStyle="solid"
            borderThickness="{slider.value}"
            borderSides="left right top bottom" />

</mx:Application>

来自：http://blog.flexexamples.com/2008/05/27/setting-a-border-on-specific-sides-of-a-numericstepper-control-in-flex/