sample.md

Spinner

Android Spinner is a view similar to the dropdown list which is used to select one option from the list of options. It provides an easy way to select one item from the list of items and it shows a dropdown list of all values when we click on it.

Sample Project

Here we will create a simple spinner having some numbers as items.

Process

Step 1 - Add Spinner widget to activity_main.xml layout.

XML Code:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
  
  <!--Adding Spinner-->

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />


</androidx.constraintlayout.widget.ConstraintLayout>

Step 2 - Add Spinner list item in form of a Array.

Here we will add the list of items in form of string-array. We will that in

• string.xml file is by default present in the project. Path - res -> Values -> string.xml

XML Code:

<resources>
  <!--App name depends upon your naming-->
  
    <string name="app_name">Spinners</string>


    <string-array name="numbers">
        <item>One</item>
        <item>Two</item>
        <item>Three</item>
        <item>Four</item>
        <item>Five</item>

    </string-array>
</resources>

Step 3 - Adding functionality in MainActivity.java

Android spinner is associated with AdapterView. So you need to use one of the adapter classes with spinner.

JAVA Code:

package com.example.spinners;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Spinner spinner =findViewById(R.id.spinner);
        // Create an ArrayAdapter using the string array and a default spinner layout
        
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,R.array.numbers, android.R.layout.simple_spinner_item);
        // Specify the layout to use when the list of choices appears
        
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // Apply the adapter to the spinner
        
        spinner.setAdapter(adapter);
        
    }
}

• Both simple_spinner_item and simple_spinner_dropdown_item is by default available in Android.

For more details please visit Andoid Official Documentation.