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This article shows you how to parse Flex language, the content is concise and easy to understand, definitely can make your eyes shine, through the detailed introduction of this article hope you can gain something.

Flex is a presentation server installed in a J2EE application server or servlet container. It has a rich user interface component and an XML-based markup language for arranging these components.

MacromediaFlex

Macromedia Flex (codenamed Royale) is a presentation server that developers can use to develop a new generation of RIAs-Rich Internet Applications. Complex Internet applications combine the usability of desktop applications with the ease of management of web applications.

Flex is a presentation server installed in a J2EE application server or servlet container. It has a rich user interface component, an XML-based markup language for arranging these components, and an object-oriented programming language for handling user interaction. What these technologies bring us is: rendering complex Internet applications using Flash Player, developing using industry standards and familiar ways for developers.

This article will focus on key parts of the Flex language. In order to run the code mentioned in this article, you may need to join Flex Beta testing. Flex runs on top of J2EE application servers such as Macromedia JRun, IBM Websphere, BEALOGY, or Apache Tomcat. Flex will support Microsoft. NET servers in the future.

Flex Introduction

Because markup languages and object-oriented programming languages are widely used, Flex, which is based on these two technologies, will also benefit from them. Markup languages are successful, and laying out user interfaces is relatively easy. MXML, the XML-based markup language introduced by Flex, will continue its success. Much like HTML, you can use MXML to lay out the user interface of your application. As an XML-based markup language, MXML has stronger structure and less syntactic ambiguity than HTML. MXML also introduces a richer set of tags than HTML. Examples: DataGrid, Tree, TabNavigator, Accordion, and Menu, which are all part of the standard label set. You can also extend MXML tags to create your own components. In addition, the difference between the two *** is that the user interface defined by MXML is run in Flash Player, which will be more attractive than traditional HTML-based, page-centric web applications.

In addition to arranging visual components, MXML can be used to define other important aspects of an application, such as defining an application as a client of a web service, or developing animations in an application to alert users to progress.

However, the programming logic provided by markup languages is still difficult to meet the needs of user interaction. In Flex, event listeners can be written in the ActionScript programming language to meet this requirement. ActionScript is a strongly typed object-oriented language based on the ECMA-262 standard, similar to other programming languages-Java and C#-and therefore easy to learn.

In summary, when writing an application in Flex, you need to set up the user interface in MXML and write the logic that responds to user interaction in ActionScript.

As a developer, you can write MXML by hand using an IDE you are familiar with (such as Eclipse or Intellij), or you can use Flex's WYSIWYG development environment (currently codenamed Brady), depending on your preferences. Even if you choose to write MXML manually, you can still use the XML schema provided by Flex to provide you with code hinting and code completion in the IDE.

The following example is the source code for a simple Flex application called HelloWord.mxml. The application has two TextInput components, and when you click Copy, the contents of the sourceTextInput are displayed in the destinationTextInput field. The following example shows how to create an application using MXML and ActionScript: define the user interface in MXML, and write copy logic for the Button component's event listener in ActionScript.

Figure 1. Copy sourceTextInput text to destinationTextInput in HelloWorld program

That's how to parse Flex. Have you learned anything or skills yet? If you want to learn more skills or enrich your knowledge reserves, please pay attention to the industry information channel.

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