In android, Layout is used to define the user interface for an app or activity and it will hold the UI elements that will appear to the user.
The user interface in an android app is made with a collection of View
and ViewGroup
objects. Generally, the android apps will contain one or more activities and each activity is a one screen of app. The activities will contain a multiple UI components and those UI components are the instances of View
and ViewGroup
subclasses.
The user interface in an android app is made with a collection of View
and ViewGroup
objects. Generally, the android apps will contain one or more activities and each activity is a one screen of the app. The activities will contain multiple UI components and those UI components are the instances of View
and ViewGroup
subclasses.
The View
is a base class for all UI components in android. For example, the EditText class is used to accept the input from users in android apps, which is a subclass of View
.
Following are the some of common View
subclasses that will be used in android applications.
Like these we have many View
subclasses available in android.
The ViewGroup
is a subclass of View
and it will act as a base class for layouts and layouts parameters. The ViewGroup
will provide an invisible containers to hold other Views or ViewGroups and to define the layout properties.
For example, Linear Layout is the ViewGroup
that contains a UI controls like button, textview, etc. and other layouts also.
Following are the commonly used ViewGroup
subclasses in android applications.
Both View
and ViewGroup
subclasses together will play a key role to create a layouts in android applications.