Android Development: Spinners with Example

What are Spinners in Android App Development?

A Spinner in Android programming is like a dropdown that is used to quickly select one value from a set of values. When you touch the spinner, it will display a dropdown with all the values that you can choose from, simply tap on the value to get it selected.

Let's see an example with Spinner

activity_mail.xml

<?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">

    <LinearLayout
        android:layout_width="409dp"
        android:layout_height="378dp"
        android:orientation="vertical"
        tools:layout_editor_absoluteX="1dp"
        tools:layout_editor_absoluteY="1dp"
        tools:ignore="MissingConstraints">
        
        <Spinner
            android:id="@+id/days_spinner"
            android:layout_width="400dp"
            android:padding="20dp"
            android:layout_height="wrap_content"
            tools:layout_editor_absoluteX="1dp"
            tools:layout_editor_absoluteY="380dp" />

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

string.xml

<resources>
    <string name="app_name">Spinners</string>

    <string-array name="days_array">
        <item>Sunday</item>
        <item>Monday</item>
        <item>Tuesday</item>
        <item>Wednesday</item>
        <item>Thursday</item>
        <item>Friday</item>
        <item>Saturday</item>
    </string-array>

</resources>

MainActivity.java

package org.code2care.android.spinners;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
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.days_spinner);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                R.array.days_array, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
                String selectedDay = parentView.getItemAtPosition(position).toString();
                String toastMessage = "Day selected: " + selectedDay;
                Toast.makeText(getApplicationContext(), toastMessage, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parentView) {
                // Do nothing
            }
        });
    }
}

We had added a listener to the Spinner, so when an item is selected, we capture it and display it as a Toast message.