Creating XML:
To create an XML file, we have following steps-> Create a ViewGroup and provide width, height and other properties-> Create Views and provide width, height and other properties
ViewGroup: ViewGroup is used to hold more than one view. In XML, we create a parent ViewGroup, which will hold all the other views and inner view groups.
View: All the UI elements in Android called views. View needs to have minimum properties like width, height and other properties.
The following is the basic syntax to create XML design syntax:
<ViewGroup width=value height=value> <View width=value height=value/> <View width=value height=value/> <View width=value height=value/> | | | </ViewGroup>
We have different types of ViewGroups. One of those is LinearLayout.
LinearLayout: This is a ViewGroup, which allows its children to align either vertical or horizontal orientation. For this ViewGroup, we must provide orientation attribute.
Ex: <LinearLayout android:layout_width=”match_parent” android:layout_height=”match_parent” android:orientation=”vertical”> | | | </LinearLayout>
Providing width and height for Views and ViewGroups: Every View and ViewGroup must be provided with some width and height. Based on our requirement, width and height can be given in pixels and density pixels. If we don’t have particular value to provide, we will go for following 2 attribute values.
wrap_content – Gives a very minimum height and width for Views or ViewGroups. Stretches based on the content. match_parent – Gives height and width for Views or ViewGroups based on it’s parent height and width.
Creating a View: For creating a View, we assign view name as tag and provide basic properties like height and width. These properties are called attributes. Every view has different attributes. The common attributes for every view are width and height.
We have different types of views in Android. Some of those are as follows
Label (or) text – TextView Textbox – EditText Button – Button Image – ImageView RadioButton – RadioButton Checkbox – Checkbox | | | |
Create an XML syntax for the following design
<?xml version=”1.0″ encoding=”utf-8″?><LinearLayout xmlns:android=”http://schemas.android.com/apk/res/android” android:layout_width=”match_parent” android:layout_height=”match_parent” android:orientation=”vertical”>
<TextView android:layout_width=”match_parent” android:layout_height=”wrap_content” android:text=”Name” />
<EditText android:layout_width=”match_parent” android:layout_height=”wrap_content” />
<TextView android:layout_width=”match_parent” android:layout_height=”wrap_content” android:text=”Mobile” />
<EditText android:layout_width=”match_parent” android:layout_height=”wrap_content” />
<Button android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Submit” /></LinearLayout>
