<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
 creationComplete="format()" backgroundColor="#FFFFFF">

  <mx:Script>
    <![CDATA[
    import mx.formatters.SwitchSymbolFormatter;               
   
    private function format():void {
     // Create Instance of the SwitchSymbolFormatter
      var switchSymbolFormatter:SwitchSymbolFormatter = new SwitchSymbolFormatter();
      // Apply formatter on the unformatted TextInput data using selectedItem from ComboBox
      formatted.text = switchSymbolFormatter.formatValue(formatString.selectedItem.toString(), unformatted.text);
    }
    ]]>
  </mx:Script>

  <mx:Panel title="SwitchSymbolFormatter Example"  width="400" height="200"
    paddingTop="10" paddingLeft="10" paddingRight="10" paddingBottom="10">

  <mx:Form>
      <mx:FormItem label="Unformatted Data:">
        <mx:TextInput id="unformatted" text="123456789" editable="false"/>
      </mx:FormItem>
      <mx:FormItem label="Format String:">
        <mx:ComboBox id="formatString" change="format()">
          <mx:ArrayCollection>
            <mx:String>#-########</mx:String>
            <mx:String>###-######</mx:String>
            <mx:String>##-###-####</mx:String>
            <mx:String>#######-##</mx:String>
        </mx:ArrayCollection>
      </mx:ComboBox>
      </mx:FormItem>
      <mx:FormItem label="Formatted Data:">
        <mx:TextInput id="formatted" editable="false"/>
      </mx:FormItem>      
    </mx:Form>
    </mx:Panel>
</mx:Application>
如果要格式化的字符串中包含“#”，可用

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
 creationComplete="format()" backgroundColor="#FFFFFF">

  <mx:Script>
    <![CDATA[
    import mx.formatters.SwitchSymbolFormatter;               
   
    private function format():void {
     // Create Instance of the SwitchSymbolFormatter and pass in mask character
      var switchSymbolFormatter:SwitchSymbolFormatter = new SwitchSymbolFormatter("*");
      // Apply formatter on the unformatted TextInput data using selectedItem from ComboBox
      formatted.text = switchSymbolFormatter.formatValue(formatString.selectedItem..toString(), unformatted.text);
    }
    ]]>
  </mx:Script>

  <mx:Panel title="SwitchSymbolFormatter Example"  width="400" height="200"
    paddingTop="10" paddingLeft="10" paddingRight="10" paddingBottom="10">

  <mx:Form>
      <mx:FormItem label="Unformatted Data:">
        <mx:TextInput id="unformatted" text="123456789" editable="false"/>
      </mx:FormItem>
      <mx:FormItem label="Format String:">
        <mx:ComboBox id="formatString" change="format()">
          <mx:ArrayCollection>
            <mx:String># *-********</mx:String>
            <mx:String># ***-******</mx:String>
            <mx:String># **-***-****</mx:String>
            <mx:String># *******-**</mx:String>
        </mx:ArrayCollection>
      </mx:ComboBox>
      </mx:FormItem>
      <mx:FormItem label="Formatted Data:">
        <mx:TextInput id="formatted" editable="false"/>
      </mx:FormItem>      
    </mx:Form>
    </mx:Panel>
</mx:Application>
自定义格式化组件需要扩展mx.formatters.Formatter,并且重写format方法
如果发生格式化错误，会给error属性返回一个字符串信息提示

package
{
  import mx.formatters.Formatter;
  // Custom formatters must extend mx.formatters.Formatter
  public class ReverseFormatter extends Formatter {
       
    public function ReverseFormatter() {
      super();
    }
    // Custom formatters must override format().
    override public function format(formatObj:Object):String         {
      if(formatObj.length == 0) {   
        // return empty string and set error property if string has zero length.
        error="Can not format an empty String";
        return ""
      } else {
       error=null;
        var returnString:String = "";
        // loop through value and build string in reverse
        for(var i:Number=formatObj.length; i>=0; i--){
          returnString = returnString + formatObj.charAt(i);
        }
        return returnString;
      }
    }
  }
}
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
   backgroundColor="#FFFFFF" width="475" height="175" xmlns:comps="*">
 
  <mx:Script>
   <![CDATA[
    import mx.controls.Alert;
   
    private function format():void{
     reversetxt.text = reverseFormatter.format(validatetxt.text);
     if(reverseFormatter.error != null){
      Alert.show(reverseFormatter.error, "Formatter Error");
     }
    }
   ]]>
  </mx:Script>
 
  <comps:ReverseFormatter id="reverseFormatter" />
 
  <mx:Panel title="Reverse Formatter" width="100%" height="100%" layout="absolute">
    <mx:TextInput id="validatetxt" width="400" change="this.format()" y="30" x="3"/>
    <mx:TextInput id="reversetxt" width="400" x="3" y="60" editable="false"/>
    <mx:Label width="400" x="3" y="5" text="Type into the field below and see the results"/>
  </mx:Panel>
</mx:Application>
自定义验证组件需要扩展mx.validators.Validator类，并重写doValidation方法

package
{
    /*
    Authored by Rich Tretola
    */
    import mx.validators.Validator;
    import mx.validators.ValidationResult;

    public class PasswordValidator extends Validator {

        private var results:Array;

        public function PasswordValidator() {
            super();
        }
        // Override the doValidation() method.
        override protected function doValidation(value:Object):Array {

            results = [];

            // Call super's doValidation().
            results = super.doValidation(value);       
            // Return if super's doValidation contains errors (required would be an example).
            if (results.length > 0){
                return results;
            }
            // Check for min length
            var dataString:String = String(value);
            if (dataString.length < 6){
             results.push(new ValidationResult(true, null, "Short", "Password must be at least 6 characters."));
             return results;
            }
            // Check for max length (this can be set in the text component's maxChars property).
            if (dataString.length > 10){
             results.push(new ValidationResult(true, null, "Long", "Password must be no larger than 10 characters."));
              return results;
            }       

            // Check for at least 1 upper case letter.
            if (dataString.search("[A-Z]")<0) {
                results.push(new ValidationResult(true, null, "Upper", "Passwords must contain at least one upper case letter."));
                return results;
            }
            // Check for at least 1 lower case letter.
            if (dataString.search("[a-z]")<0) {
                results.push(new ValidationResult(true, null, "Lower", "Passwords must contain at lease one lower case letter."));
                return results;
            }
            // Check for at least 1 number.
            if (dataString.search("[0-9]")<0) {
                results.push(new ValidationResult(true, null, "Number", "Passwords must contain at least one number."));
                return results;
            }
            return results;
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
   backgroundColor="#FFFFFF" width="550" height="300" xmlns:comps="*">
 
  <comps:PasswordValidator required="true" source="{passwordtxt}" property="text"
    trigger="{validatebtn}" triggerEvent="click" listener="{passwordtxt}"/>
 
  <mx:Panel title="Password Validator" width="350" height="150">
   <mx:TextArea width="100%" height="45" editable="false" borderStyle="none"
    text="Password must be between 6-10 characters and contain at least 1 upper case, 1 lower case, and 1 number." />
    <mx:HBox paddingLeft="3">
      <mx:TextInput id="passwordtxt" width="75"/>
      <mx:Button id="validatebtn" label="Validate Password"/>   
    </mx:HBox>
  </mx:Panel>
</mx:Application>