Macromedia flex 2 Manuale

124

Creating Simple Visual Components in ActionScript

In this example, you first define the 

MyComp

 namespace to specify the location of your custom 

component. You then reference the component as an MXML tag by using the namespace 
prefix. 

You can specify any inherited properties of the superclass in MXML, as the following example 
shows:

<?xml version="1.0"?> 
<!-- as/MainDeleteTextAreaProps.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
    xmlns:MyComp="myComponents.*">
  
    <MyComp:DeleteTextArea wordWrap="true" text="My Message"/>
  
</mx:Application>

You do not have to change the name of your custom component when you create a subclass of 
a Flex class. In the previous example, you could have named your custom component 
TextArea, and written it to the TextArea.as file in the myComponents directory, as the 
following example shows:

package myComponents
{

import mx.controls.TextArea;
import flash.events.KeyboardEvent;

public class TextArea extends mx.controls.TextArea {

...

}

}

You can now use your custom TextArea control, and the standard TextArea control, in an 
application. To differentiate between the two controls, you use the namespace prefix, as the 
following example shows:

<?xml version="1.0"?> 
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 

xmlns:MyComp="myComponents.*" >

  
    <MyComp:TextArea/>
    
    <mx:TextArea/>
  
</mx:Application>

NOT

E

Your class must be specified as 

public

 for you to be able to access it by using an MXML 

tag.