In this tutorial we will learn about how to create radio button in android studio, and show a toast message of radio button value when user select it and radio button android example .
Radio Button
Android Radio buttons are used to show the multiple options, to select one option from it. Android radio button is allow the user to select one options from a group of options at a time.
Radio buttons allow the user to select one option from a set. You should use radio buttons for optional sets that are mutually exclusive . Radio button has two states, either checked or unchecked. Unlike checkbox, changes in the state of a radio button will affect other radio buttons. Radio button is an android widget, that belong to android.widget.RadioButton class.
Radio Group
RadioButtons android are used together in a radio group. RadioGroup is a group of radio buttons. Radio group is a widget of android.widget.RadioGroup class . Initially radio buttons are in unchecked state, Checking one radio button that belongs to a radio group unchecked any other checked radio button within the group . It means at one time only one radio button could be checked.
1. Create a New Project :
Lets we start with a new project in Android Studio from File New Project ⇒
select Empty Activity and go through it.
2. Create a RadioButton to your main layout file :
First we create a radio group then create the radio buttons inside the radio group to your main layout file i.e. activity_main.xml of your Main_Activity.java file or just implement the following xml code.
<RadioGroup
android:id="@+id/radioGroup"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_margin="10dp"
tools:ignore="MissingConstraints">
<RadioButton
android:id="@+id/radioButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Android"
android:textSize="15sp"/>
<RadioButton
android:id="@+id/radioButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Java"
android:textSize="15sp"/>
<RadioButton
android:id="@+id/radioButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Php"
android:textSize="15sp"/>
<RadioButton
android:id="@+id/radioButton4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Mysql"
android:textSize="15sp"/>
</RadioGroup>
activity_main.xml :
<?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=".TestActivity"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Please select a course :-"
android:textColor="@android:color/black"
android:layout_marginRight="12dp"
android:layout_marginLeft="13dp"
android:layout_marginTop="4dp"
android:textSize="21sp"/>
<RadioGroup
android:id="@+id/radioGroup"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_margin="10dp"
tools:ignore="MissingConstraints">
<RadioButton
android:id="@+id/radioButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Android"
android:textSize="15sp"/>
<RadioButton
android:id="@+id/radioButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Java"
android:textSize="15sp"/>
<RadioButton
android:id="@+id/radioButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Php"
android:textSize="15sp"/>
<RadioButton
android:id="@+id/radioButton4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Mysql"
android:textSize="15sp"/>
</RadioGroup>
</LinearLayout>
3. Implement OnCheckedChangeListener to radio group :
Now implement setOnCheckedChangeListener of radio group to perform an action or event on radio buttons, like toast message in MainActivity.java file or just add the following code .
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
// checkedId is the Id of the RadioButton selected
RadioButton radioButton=(RadioButton)findViewById(checkedId);
Toast.makeText(getApplicationContext(), radioButton.getText(), Toast.LENGTH_SHORT).show();
}
});
MainActivity.java :
package net.technxt.radiobutton;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;
public class TestActivity extends AppCompatActivity {
RadioGroup radioGroup;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
radioGroup = (RadioGroup)findViewById(R.id.radioGroup);
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
// checkedId is the Id of the RadioButton selected
RadioButton radioButton=(RadioButton)findViewById(checkedId);
Toast.makeText(getApplicationContext(), radioButton.getText(), Toast.LENGTH_SHORT).show();
}
});
}
}
Now run the project/app to test radio button in android app through android device or any Emulator .