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 >