AS3 / AIR桌面应用程序：我无法在s：Textarea上输入越南语

Question

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:mx="library://ns.adobe.com/flex/mx"
                       xmlns:s="library://ns.adobe.com/flex/spark">
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
    <fx:Script>  
        <![CDATA[
            private function resetPrompts():void { 
                myTextInput.text = ""; 
                myTextArea.text = ""; 
            } 
        ]]>  
    </fx:Script>  
    <s:VGroup>
        <s:TextInput id="myTextInput" prompt="Enter name..." fontFamily="Marker Felt Thin" /> 
        <s:TextArea id="myTextArea" prompt="Triệu hổ..." fontFamily="A"/> 
        <s:Button label="Reset" click="resetPrompts()"/> 
    </s:VGroup>

</s:WindowedApplication>

作为我的代码：我使用此工具编写越南语字符： http ://unikey.vn/vietnam/，但所有特殊字符：ê，ô，í，ì...已被删除。