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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

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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.
Bharti
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
Daniel
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Introduction to xml. OpenStax CNX. Dec 02, 2014 Download for free at https://legacy.cnx.org/content/col11207/1.18
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