Radio Button, ImageView and Toast Usage in Android

File Name: activity_main.xml

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

    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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.abbu.radio_power.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Enquire Teacher-in-Charge"
        android:id="@+id/textView" />

    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/choices"
        android:layout_below="@+id/textView"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true">

    <RadioButton
        android:text="Computer Science"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_marginStart="5dp"
        android:layout_marginTop="10dp"
        android:id="@+id/radioButtonCS" />

    <RadioButton
        android:text="Commerce"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/radioButtonCS"
        android:layout_toEndOf="@+id/textView"
        android:layout_alignParentStart="false"
        android:layout_marginStart="5dp"
        android:layout_marginTop="10dp"
        android:id="@+id/radioButtonCO" />

    <RadioButton
        android:text="Chemistry"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/radioButtonEL"
        android:layout_alignStart="@+id/radioButtonCO"
        android:layout_alignParentStart="false"
        android:layout_marginStart="5dp"
        android:layout_marginTop="10dp"
        android:id="@+id/radioButtonCH" />

    <RadioButton
        android:text="Electronics"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/radioButtonEL"
        android:layout_alignParentStart="false"
        android:layout_marginStart="5dp"
        android:layout_marginTop="10dp"
        android:layout_below="@+id/radioButtonCS"
        android:layout_alignStart="@+id/radioButtonCS" />
    

    </RadioGroup>

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:srcCompat="@mipmap/ic_launcher"
        android:id="@+id/imageView"
        android:layout_marginTop="41dp"
        android:layout_below="@+id/choices"
        android:layout_centerHorizontal="true" />
</RelativeLayout>

File Name: MainActivity.java

package com.example.abbu.radio_power;

import android.content.res.TypedArray;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private TypedArray images;
    private ImageView itemImage;
    RadioButton rch = null;
    RadioButton rco = null;
    RadioButton rcs = null;
    RadioButton rel = null;
    RadioGroup rg = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        images = getResources().obtainTypedArray(R.array.radiobtn_image);
        itemImage = (ImageView) findViewById(R.id.imageView);
        rch = (RadioButton) findViewById(R.id.radioButtonCH);
        rco = (RadioButton) findViewById(R.id.radioButtonCO);
        rcs = (RadioButton) findViewById(R.id.radioButtonCS);
        rel = (RadioButton) findViewById(R.id.radioButtonEL);
        rg = (RadioGroup) findViewById(R.id.choices);

        rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                if(checkedId == rch.getId()) {
                    itemImage.setImageResource(R.drawable.pic2);
                    Toast.makeText(MainActivity.this, "Dr. Neelu Dhir",
                            Toast.LENGTH_SHORT).show();
                }else if (checkedId == rco.getId()) {
                    itemImage.setImageResource(R.drawable.pic4);
                    Toast.makeText(MainActivity.this, "Ms. Sangeeta Relan",
                            Toast.LENGTH_SHORT).show();
                } else if (checkedId == rcs.getId()) {
                    itemImage.setImageResource(R.drawable.pic1);
                    Toast.makeText(MainActivity.this, "Dr. Vibha Gaur",
                            Toast.LENGTH_SHORT).show();
                } else {
                    itemImage.setImageResource(R.drawable.pic3);
                    Toast.makeText(MainActivity.this, "Dr. Ravneet Kaur",
                            Toast.LENGTH_SHORT).show();
                }
            }
        });
}
}

File Name: strings.xml

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

    <string-array name="radiobtn_image">
        <item>@drawable/pic1</item>
        <item>@drawable/pic2</item>
        <item>@drawable/pic3</item>
        <item>@drawable/pic4</item>
    </string-array>
</resources>

Output:
Radio Button, ImageView and Toast Usage in Android
Radio Button, ImageView and Toast Usage in Android