Alert control uses the alertForm proerpty. If you go through the AlertForm.as in the mx.controls.alertClasses package, there is an internal textField property (a UITextField object). By setting this property to false, the text cannot be selected.
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="absolute"
width="320"
height="240"
backgroundGradientColors="[#ffffff, #b0b0ff]"
>
<mx:Script>
<![CDATA[
import mx.controls.Alert;
private var _alert:Alert;
private function showAlert():void{
Alert.show("This is a selectable text.");
}
private function showNonAlert():void{
_alert = Alert.show("This is a non-selectable text.");
/*
You can’t always depend on this behavior to work, because the mx_internal
namespace may not be available in future versions of the Flex SDK.
*/
_alert.mx_internal::alertForm.mx_internal::textField.selectable = false;
}
]]>
</mx:Script>
<mx:Button horizontalCenter="0" verticalCenter="5"
label="Selectable text alert dialog[default]"
click="showAlert();"
/>
<mx:Button horizontalCenter="0" verticalCenter="-35"
label="Non-selectable text alert dialog"
click="showNonAlert();"
/>
</mx:Application>