Android Spinner and Adapter Tutorial

Spinner

• Spinner is a widget that provides a quick way to select one value from a set of values in Android
• It is similar to a drop-down list seen in other programming languages
• By default, a spinner shows its currently selected value
• Spinner is associated with an Adapter view to fill data in the spinner

Adapter and Adapter Views

• An adapter is a bridge between the UI component and data source that helps to fill data in UI components
• It holds data and sends it to the adapter view, which then shows the data on different views like ListView, GridView, and Spinner
• ArrayAdapter is used when you have a list of single-type items backed by an array
• Examples include a list of phone contacts, countries, or names

ArrayAdapter Syntax

• ArrayAdapter(Context context, int resource, int textViewResourceId, T[] objects)
• context: the first parameter is used to pass the context, which is a reference to the current class
• resource: the second parameter is the resource ID used to set the layout (XML file) for list items
• textViewResourceId: the third parameter is used to set the ID of the TextView where you want to display the actual text
• objects: the fourth parameter is an array of objects used to set the array of elements in the TextView

Example of Spinner

• Create a Spinner in activity_main.xml and MainActivity.java files
• Use ArrayAdapter to fill the Spinner with data
• Set the OnItemSelectedListener to perform actions when an item is selected

Menu in Android

• There are three types of menus in Android: Option Menu, Context Menu, and Pop-up Menu