Flex 动态绑定BindingUtils.bindProperty

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
    layout="absolute" initialize="init();">

    <mx:Script>
        <!--[CDATA[
            import mx.binding.utils.BindingUtils;
            import mx.binding.utils.ChangeWatcher;

            
            private var watcher1:ChangeWatcher;
            private var watcher2:ChangeWatcher;

            /**
             * 动态绑定
             * @return void
             * **/
            private function Binding():void {

                //绑定ID为txt2的txtInput
                //绑定属性为txtInput的text
                //监视者ID为txt1的txtInput
                //监视者属性为txtInput的text
                watcher1 = BindingUtils.bindProperty(txt2,"text",txt1,"text");

                //绑定ID为txtComb的txtInput
                //绑定属性为txtInput的text
                //监视者ID为comb的ComboBox
                //监视者属性为ComboBox的value
                watcher2 = BindingUtils.bindProperty(txtComb,"text",comb,"value");
            }

            /**
             * 解除绑定
             * @return void
             * **/
            private function UnBinding():void {
                //解除绑定
                watcher1.unwatch();
                watcher2.unwatch();
            }        
        ]]-->
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Button label="动态绑定" click="Binding();"/>
        <mx:Button label="解除绑定" click="UnBinding();"/>
    </mx:ApplicationControlBar>

    

    <mx:VBox width="200" height="200">

        <mx:Spacer height="30"/>

        <mx:TextInput id="txt1"/>
        <mx:TextInput id="txt2"/>

        <mx:Spacer height="30"/>

        <mx:ComboBox id="comb">
            <mx:dataProvider>
                <mx:Array>
                    <mx:String>Beijing</mx:String>
                    <mx:String>Shanghai</mx:String>
                    <mx:String>Hangzhou</mx:String>
                </mx:Array>
            </mx:dataProvider>
        </mx:ComboBox>

        <mx:TextInput id="txtComb"/>
        </mx:VBox>
</mx:Application>