Android Studio Create Custom Spinner

Android Studio Create Custom Spinner

In this Android Studio tutorial we are going to learn Create Custom Spinner in Android, according to Android documentation Spinners provide a quick way to select one value from a set. In the default state, a spinner shows its currently selected value. Touching the spinner displays a dropdown menu with all other available values, from which the user can select a new one.

So first of all you need to open your Android Studio and create a New Project, after that choose your API Level for this article iam using API Level 22.

Because we are using a custom layout for our Spinner, so for this you need to create a new layout,right click on your layout folder, and create Layout resource file like this. iam going name it 

spinner_layout.xml.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:orientation="vertical"

    android:layout_height="match_parent">

      <TextView

        android:id="@+id/textView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_weight="1"

        android:textAppearance="?android:textAppearanceLarge"

        android:layout_gravity="center_horizontal"

        android:text="Example" />

</LinearLayout>

Now we are going to create a new Java class, iam going to name it SpinnerAdapter.java. this class extends from BaseAdapter, and after that you need to implement the interface for this class. basically we are going to create three variables, and after that you need to create constructor for your class, you can press alt+insert to create constructor in Android Studio.

import android.app.Activity;

import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.TextView;

import java.util.List;

 /**

 * Created by Parwiz on 7/28/2020.

 */

public class SpinnerAdapter extends BaseAdapter {

     //our variables

    private List<String> listItem;

    private Activity activity;

    private LayoutInflater inflater;

      // constrcutor for the class, press alt+insert for creating

    //constrcutor

    public SpinnerAdapter(List<String> listItem, Activity activity) {

        this.listItem = listItem;

        this.activity = activity;

        this.inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }

     @Override

    public int getCount() {

        return listItem.size();

    }

     @Override

    public Object getItem(int i) {

        return i;

    }

     @Override

    public long getItemId(int i) {

        return i;

    }

     @Override

    public View getView(int i, View view, ViewGroup viewGroup) {

          //we have inflated the layout in here

        View v = view;

         if(view == null)

            v = inflater.inflate(R.layout.spinner_layout, null);

        TextView tv = v.findViewById(R.id.textView);

        tv.setText(listItem.get(i));

        return v;

    }

}

This is our MainActivity.java class. we have created the object of our SpinnerAdapter class.

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.widget.Spinner;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    List<String> listData = new ArrayList<>();

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        createList();

        Spinner spinner = findViewById(R.id.spinner);

        SpinnerAdapter adapter = new SpinnerAdapter(listData, MainActivity.this);

        spinner.setAdapter(adapter);

    }

    private void createList() {

        for(int i = 0; i <10; i++) {

            listData.add("Item"+ i);

        }

    }

}

In our main_activity.xml we have just added a Spinner widget.

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.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="org.codeloop.parwiz.customspinner.MainActivity">

    <Spinner

        android:id="@+id/spinner"

        android:layout_width="368dp"

        android:layout_height="wrap_content"

        android:layout_marginEnd="8dp"

        android:layout_marginStart="8dp"

        android:layout_marginTop="68dp"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintHorizontal_bias="0.0"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>