SPINNER Widget Tutorials on Android

SPINNER IN ANDROID:-

It is used to create a drop-down list in the android application, Spinner contains a set of items and it will display items when we click on it.

Spinner can be implemented in two different ways:-

1)  Default Spinner:-

    This Spinner widget displays only Single Column data, similar to the drop-down list.

2)  Custom Spinner:-

If we want to display more than one column, in Spinner Widget then we can use Custom Spinner.

for example, if we want to show the flag of the country and country name both then we use the custom spinner.

Spinner Widget has two different components:-

1) Data Source:-

It contains the collection of data using ArrayList, Vector, or other collection objects or Array Objects.

2)  ArrayAdpater:-

It is a predefined class of Java that is used to connect from Array and other collection objects.

Spinner data will be displayed by ArrayAdapter and ArrayAdapter will connect from Data Source.

Normal array adapter only displays single column value hence if we want to display multiple column fields or Generic type data then we can create CustomeAdapter.

Syntax of Spinner:-

<Spinner
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/sp"
    >

</Spinner>

Events of Spinner:-

We will use setOnItemSelectedListner() to manage Spinner Event. It will provide two different event method

1)  onItemSelected()

2)  onNothingSelected()

Example of Spiiner

1)  Create Activity and Write Following code in XML File.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:paddingTop="50dp"
    tools:context=".MainActivity13">

    <Spinner
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:id="@+id/sp"

        >

    </Spinner>

</LinearLayout>

2)   Write Java Program Code:-

package com.example.additionapplication;

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 MainActivity13 extends AppCompatActivity {

    String country[] = {"Select Country","INDIA","USA","JAPAN","CHINA","UK"};
    Spinner spin;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main13);
        spin = findViewById(R.id.sp);
        ArrayAdapter aa = new ArrayAdapter(this,android.R.layout.simple_spinner_item,country);
        spin.setAdapter(aa);
       spin.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
           @Override
           public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
               Toast.makeText(getApplicationContext(),"Selected Country Is "+country[position],Toast.LENGTH_SHORT).show();
           }

           @Override
           public void onNothingSelected(AdapterView<?> parent) {

           }
       });


    }
}

STEP FOR CUSTOM SPINNER;

1)  CREATE ACTIVITY

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".MainActivity16">

    <Spinner
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/custspin"
        ></Spinner>

</LinearLayout>

2)  Create Layout xml file:-

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:orientation="horizontal"
    android:layout_height="match_parent">

    <ImageView
        android:layout_width="100dp"
        android:layout_height="50dp"
        android:id="@+id/custimgview"
        >

    </ImageView>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/custtextview"
        ></TextView>

</LinearLayout>

3)  Create Adapter class:-

package com.example.additionapplication;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;



public class StuAdapter extends BaseAdapter {
    int imgid[];
    String sname[];
    Context ctx;
    LayoutInflater inflter;
    StuAdapter(Context ctx,int imgid[],String sname[])
    {
        this.imgid = imgid;
        this.sname=sname;
        this.ctx =ctx;
        inflter = (LayoutInflater.from(ctx));
    }
    @Override
    public int getCount() {
        return sname.length;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View row = inflter.inflate(R.layout.custspinner_layout, parent, false);
        ImageView img = (ImageView) row.findViewById(R.id.custimgview);
        img.setImageResource(imgid[position]);
        TextView label = (TextView) row.findViewById(R.id.custtextview);
        label.setText(sname[position]);
        return row;
    }
}


4)  Create MainActivity 

package com.example.additionapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.Spinner;

public class MainActivity16 extends AppCompatActivity {

    Spinner sp;
    int imgid[] = {R.drawable.bg,R.drawable.sss};
    String str[] = {"RAMESH","SURESH"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main16);
        sp = findViewById(R.id.custspin);
        StuAdapter obj = new StuAdapter(getApplicationContext(),imgid,str);
        sp.setAdapter(obj);

    }
}