MACROMEDIA FLEX-GETTING STARTED WITH FLEX Uživatelský manuál stáhnout pdf (Strana 101)

images don’t have to be local; they can be any URL, pointing

to any server. So, the list could be a set of URLs to various

images. And that list could easily be loaded from an external

XML file using the HTTP support in Flex.

Back to the example at hand: I like the functionality, but the

presentation is a little bland. So, let’s make it more interesting

by showing thumbnails of the images in the list. I do that in

Example 6-4.

Example 6-4. Pictures2.mxml

<?xml version="1.0" encoding="utf-8"?>

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"

layout="horizontal"

horizontalAlign="left">

<mx:Array id="images">

<mx:String>megan1.jpg</mx:String>

<mx:String>megan2.jpg</mx:String>

<mx:String>megan3.jpg</mx:String>

<mx:String>megan4.jpg</mx:String>

<mx:String>megan5.jpg</mx:String>

</mx:Array>

<mx:List id="ctlImage" dataProvider="{images}"

selectedIndex="0" width="50">

<mx:itemRenderer>

<mx:Component>

<mx:Image source="{data}” width="50” height="50” />

</mx:Component>

</mx:itemRenderer>

</mx:List>

<mx:Image source="{ctlImage.selectedItem.valueOf()}"

height="400" />

</mx:Application>

The only thing that has changed in this code is that I have added

an itemRenderer to the list. That is an optional attribute that

you can add to Flex controls so that you can render each cell

in a table or list yourself. In this case, I provide an inline com-

ponent that creates an mx:Image for each cell in the list.

I then run this in Flex Builder; the result appears in Figure 6-5.

Now I have thumbnails instead of images. Yes, it’s really that

easy. The item rendering and component support in Flex is

A Simple Image Viewer | 85

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MACROMEDIA FLEX-GETTING STARTED WITH FLEX Uživatelský manuál Strana 101