Eclipse Mobile Mousw Manual de usuario descargar pdf (Pagina 17)

The sample application contains a single activity and a single view. The application

contains a file named main.xml that represents the visual aspects of the primary UI

of the activity. Note that there is no reference in the main.xml where the layout is

used. This means it may be used in more than one activity, if desired. Listing 5

contains the content of the layout file.

Listing 5. Layout file

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Hello World, SaySomething"

</LinearLayout>

This is the most simplistic of layouts. There is a single linear layout, which is oriented

as a vertical layout, meaning all contained elements are in a single column. There is

a single TextView element, which can be likened to a label in other development

environments. A TextView represents static text that is not editable.

Note that each view element (layout and TextView in this example) have

attributes in the Android name space. Some attributes are common to all views —

the android:layout_width and android:layout_height attributes, for

example. The values available for these attributes are:

Fill Parent

This extends the view element to take the maximum space available. This can

also be thought of as meaning "stretch."

Wrap Content

This value tells Android to paint the elements one after the next without

stretching.

During the build process, all resources are compiled. One of the products of that

process is the R.java file, which represents the resources to the remainder of the

application. The R.java file is discussed next.

R.java

The R.java file is created upon build automatically, so be sure to not modify it by

hand as all changes will be lost. Listing 6 contains the R.java file for the sample

application.

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Eclipse Mobile Mousw Manual de usuario Pagina 17