Once we are done with the creation of layout with UI controls, we need to load the XML layout resource from our activity onCreate() callback method like as shown below. Note: we need to create a user interface ( UI) layout files in /res/layout project directory, then only the layout files will compile properly. In android, each input control is having a specific set of events and these events will be raised when the user performs particular action like, entering the text or touches the button. Once we define the root element, then we can add additional layout objects or widgets as a child elements to build View hierarchy that defines our layout.įollowing is the example of defining UI controls ( TextView, EditText, Button) in the XML file ( activity_main.xml) using LinearLayout. The layout file must contain only one root element, which must be a View or ViewGroup object. In android, we can create layouts same as web pages in HTML by using default Views and ViewGroups in the XML file. The android framework will allow us to use either or both of these methods to define our applicationâs UI. In android, we can define a UI or input controls in two ways, those are To know more about View and ViewGroup in android applications, check this Android View and ViewGroup. The ViewGroup will provide invisible containers to hold other Views or ViewGroups and to define the layout properties. The ViewGroup is a subclass of View and it will act as a base class for layouts and layout parameters. and it is responsible for event handling and drawing. The View is a base class for all UI components in android and it is used to create interactive UI components such as TextView, EditText, Checkbox, Radio Button, etc. Generally, in android the user interface of an app is made with a collection of View and ViewGroup objects. In android we have a wide variety of UI or input controls available, those are TextView, EditText, Buttons, Checkbox, Progressbar, Spinners, etc.įollowing is the pictorial representation of user interface (UI) or input controls in android application. The value for this attribute must be the name of the method you want to call in response to a click event. To define the click event handler for a checkbox, add the android:onClick attribute to the element in your XML layout.In android UI or input controls are the interactive or View components that are used to design the user interface of an application. When the user selects a checkbox, the CheckBox object receives an on-click event.
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