Flex圆角矩形

<?xml version="1.0" encoding="utf-8"?>
<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 corners:Array = [];
                if (tLeft.selected) {
                    corners.push("tl");
                }
                if (tRight.selected) {
                    corners.push("tr");
                }
                if (bLeft.selected) {
                    corners.push("bl");
                }
                if (bRight.selected) {
                    corners.push("br");
                }
                var str:String = corners.join(" ");
                textInput.setStyle("focusRoundedCorners", str);
                focusManager.setFocus(textInput);
            }
        ]]>
    </mx:Script>  

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="top left (tl):">
                <mx:CheckBox id="tLeft"
                             selected="true"
                             change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="top right (tr):">
                <mx:CheckBox id="tRight"
                             selected="true"
                             change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="bottom left (bl):">
                <mx:CheckBox id="bLeft"
                             selected="true"
                             change="checkBox_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="top right (br):">
                <mx:CheckBox id="bRight"
                             selected="true"
                             change="checkBox_change(event);" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>  

    <mx:TextInput id="textInput"
                  focusThickness="10"
                  cornerRadius="10" />
    <mx:Button/>  

</mx:Application>

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">  

    <mx:TextInput id="textInput"
            focusThickness="10"
            cornerRadius="10"
            focusRoundedCorners="tl br" />  

</mx:Application>  

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">  

    <mx:Style>
        TextInput {
            focusRoundedCorners: "tl br";
        }
    </mx:Style>  

    <mx:TextInput id="textInput"
            focusThickness="10"
            cornerRadius="10" />  

</mx:Application>