Writing WML files based on the Wireless Markup Language (WML)

The Infinite Markup Language WML (Wireless Markup Language) is a language based on the Extensible Markup Language XML (Extension Markup Language), which is a subset of XML. It can display a variety of text, images and other data, is proposed by the WAP Forum (http://www.wapforum.org) and specifically for wireless device users to provide interactive interface and design, the current version of the 1.1 version. These wireless devices include mobile phones, pagers and personal digital assistants PDA (Personal Digital assistants).

　　 1, WML and WAP equipment

To better understand and use the WML language, developers should have a general understanding of the characteristics and characteristics of the devices used by WML and the devices that support WML.

Generally speaking, the wireless devices used by WML have the following characteristics:

Compared with the ordinary personal computer, the volume is small;

The device has limited memory and its CPU performance is limited;

The communication bandwidth is narrower and the delay is longer.

In the case of mobile phones and PDAs, devices supporting WML have the following characteristics:

There is a display screen that can display support for numbers and character input;

Support the operator to use arrows or digital buttons to select;

Printable code that supports ASCII;

There are usually two programmable function keys, that is, the Accpet key and the options key, generally arranged in close to the keyboard screen;

There is usually a prev navigation key.

The purpose of the WAP device used in WML is to understand the characteristics of the WML language through the features and characteristics of the WAP device, and to have a general idea of the problems to be solved by WML programming.

　　 2, use the text editor face to write WML program

When you write a WAP Web page or application using the WML language, you need to edit it using an editor. As with HTML programming, WML programs are plain file text that can be written using any text editor, such as Notepad in a Windows system. You can also use software such as Nokia WAP Toolkie (for this specific usage will be brought up later in the learning process). Let's first introduce the first method and then introduce the second one.

If you want to use Notepad to write a WML program, you can start the Notepad program on the Windows system by clicking the Start button and then pointing to Programs, attachments, Notepad, and then from the menu that appears. The screen will then appear in its editing window, from which you can enter and write WML programs.

As an example, we can enter the following simple program.

<?xml version= "1.0"? > >
! DOCTYPE WML public "-//wapforun//dtd WML 1.1//en" "Http://www.wapforum.org/DTD/wml_1.1.xml"
<xml>
<card id= "Card1" title= "title"
<p>
!--Write your Card implementation here.-->
Hello world!!
</P>
</card>
</xml>
Save it as a Hello.xml file when you have finished losing it. Note that the file name extension should be XML instead of TXT when saving.