设置TextInput控件获得焦点时边框的某一角为圆角.

TextInput控件的focusRoundedCorners样式学习.
示例：

代码：

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/12/rounding-specific-corners-on-a-focus-rectangle-in-the-textinput-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 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:Application>

你可以在标签内直接设置属性：

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/12/rounding-specific-corners-on-a-focus-rectangle-in-the-textinput-control-in-flex/ -->
<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>

或者通过CSS设置：

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/12/rounding-specific-corners-on-a-focus-rectangle-in-the-textinput-control-in-flex/ -->
<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>