Here is a list of the available CSS styles for TextFields in ActionScript 3. Sorry, there is no corner radius.
You can turn on a border for a textfield on the TextField objects border property. But there is not a property available to round the corner.
I suggest you create a new component and add the border yourself as a Sprite underneath the TextField. Something like:
package
{
import flash.display.Graphics;
import flash.display.Sprite;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;
public class TextBorder extends Sprite
{
private static const CORNER_RADIUS:int = 5;
// display objects
private var background:Sprite;
private var field:TextField;
// properties
private var _text:String;
public function TextBorder()
{
background = new Sprite;
field = new TextField;
field.autoSize = TextFieldAutoSize.LEFT;
addChild(background);
addChild(field);
// TESTING:
text = "Hello World";
}
public function set text(newText:String):void
{
_text = newText;
display();
}
public function get text():String
{
return _text;
}
private function display():void
{
field.text = _text;
var g:Graphics = background.graphics;
g.clear();
g.lineStyle(0, 0x0);
g.beginFill(0xFFFFFF);
g.drawRoundRect(0, 0, field.width, field.height, CORNER_RADIUS);
}
}
}