<< Chapter < Page Chapter >> Page >

An Image control

The Flex 3 documentation tells us:

The Image control lets you import JPEG, PNG, GIF, and SWF files at runtime. You can also embed any of these files and SVG files at compile timeby using @Embed(source='filename').

The primary output that is produced by compiling a Flex application is an swf file that can be executed in Flash Player.

The documentation goes on to explain that by using @Embed , you can cause resources such as images to be embedded in the swf file.

The advantage to embedding is that embedding the resource eliminates the requirement to distribute the resource files along with the swf files. Thedisadvantage is that it causes the swf file to be larger.

Import an image

Listing 4 imports an image from the file named myimage.jpg that is located in the src folder of the project tree. This image is embedded in the swf file when the Flex application is compiled.

Import an image.

<mx:Image id="myimg" source="@Embed('myimage.jpg')" height="250"></mx:Image></mx:Application>

The id property

Setting the id property on the image to myimg makes it possible to refer to the image in the change-event code in Listing 3.

(Note that there is no requirement to set the value of the id property to be the same as the name of the image file as was done in Listing 4.)

The height property

Setting the height property of the image to 250 pixels in Listing 4 causes the image height to be 250 pixels when it is first displayed as shown inFigure 1.

The end of the application

Listing 4 contains the closing tag for the Application element signaling the end of the Flex 3 application named SliderChangeEvent01 .

The hybrid Flex3-4 project named SliderChangeEvent02

The mxml project code

The mxml code for this project is shown in its entirety in Listing 7.

If you examine this code you will see that:

  • It uses a Flex 4 spark s:Application element instead of a Flex 3 mx:Application element.
  • It declares the standard set of Flex 4 namespaces.
  • It uses a spark s:VGroup element as the container for the following Flex 3 components. (Note that the Flex 3 project in Listing 6 doesn't require another container in addition to the mx:Application container.) :
    • mx:Label
    • mx:Label
    • mx:HSlider
    • mx:Image

Otherwise, the mxml code for this project is the same as the code for the Flex 3 project shown in Listing 6. The mixture of spark and mx componentscauses this to be a hybrid Flex 3-4 project.

Visual appearance of the project

If you run the online version of the project named SliderChangeEvent02 , you should see an initial screen display similar to Figure 7.

Browser image at startup for the hybrid project.

Missing image.
Browser image at startup for the hybrid project.

Compare with the Flex 3 project

By comparing this screen output for the hybrid project with the screen output for the Flex 3 project in Figure 1, you can immediately spot several significantdifferences:

  • The background is white instead of gray.
  • The labels, the slider, and the image are not centered horizontally in the browser window.
  • The appearance of the thumb on the slider is a circle instead of a triangle.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Introduction to xml. OpenStax CNX. Dec 02, 2014 Download for free at https://legacy.cnx.org/content/col11207/1.18
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Introduction to xml' conversation and receive update notifications?