Android Radio Group Using Kotlin With Example

In this article, we will learn about android Radio Group using Kotlin. We will go through various example that demonstrates how to use different attributes of Radio Group. For example, …..

In this article, we will get answer to questions like –

What is Radio Group?
Why should we consider Radio Group while designing ui for any app?
What are possibilities using Radio Group while designing ui? etc.

Let’s have a quick demo of things we want to cover in this tutorial –

Output

Tutorialwing Android Radio Group Output

Getting Started

We can define android Radio Group widget as below –

Radio Group is used to create a multiple-exclusion scope for a set of radio buttons i.e. You can select only one radio button out of all radio buttons present in any radio group. Selecting one radio button automatically de-select previously selected radio button.

Now, how do we use Radio Group in android application ?

Creating New Project

At first, we will create an application.
So, follow steps below to create any android project in Kotlin –

Step	Description
1.	Open Android Studio (Ignore if already done).
2.	Go to File => New => New Project. This will open a new window. Then, under Phone and Tablet section, select Empty Activity. Then, click Next.
3.	In next screen, select project name as WIDGET_PROJECT_NAME. Then, fill other required details.
4.	Then, clicking on Finish button creates new project.

Newbie in Android ?

Some very important concepts (Recommended to learn before you move ahead)

Install Android Studio

Create New Project in Android Studio

Android Project Structure

Run / Debug / Test Android App

Before we move ahead, we need to setup for viewBinding to access Android Radio Group Using Kotlin file without using findViewById() method.

Setup ViewBinding

Add viewBinding true in app/build.gradle file.

 
 android { 
 	// OTHER CODE... 
 	buildFeatures { 
 		viewBinding true 
 	} 
 }

Now, set content in activity using view binding.
Open MainActivity.kt file and write below code in it.

 
 class MainActivity : AppCompatActivity() { 
 	
 	private lateinit var binding: ActivityMainBinding 
 	
 	override fun onCreate(savedInstanceState: Bundle?) { 
 		super.onCreate(savedInstanceState) 
 		binding = ActivityMainBinding.inflate(layoutInflater) 
 		val view = binding.root 
 		setContentView(view) 
 	} 
 }

Now, we can access view in Kotlin file without using findViewById() method.

Using Radio Group in Kotlin

Follow steps below to use Radio Group in newly created project –

Open res/values/strings.xml file. Then, add below code into it –

<resources>
    <string name="app_name">RadioGroup</string>
    <string name="male">Male</string>
    <string name="female">Female</string>
</resources>

Open res/layout/activity_main.xml file. Then, add below code in it –

<?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">

    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingStart="20dp"
        android:paddingEnd="20dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent">

        <RadioButton
            android:id="@+id/radioMale"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:text="@string/male"/>

        <RadioButton
            android:id="@+id/radioFemale"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:text="@string/female"/>

    </RadioGroup>

</androidx.constraintlayout.widget.ConstraintLayout>

We can also access it in Kotlin File, MainActivity.kt, as below –

package com.tutorialwing.radiogroup

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import com.tutorialwing.radiogroup.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

	private lateinit var binding: ActivityMainBinding

	override fun onCreate(savedInstanceState: Bundle?) {
		super.onCreate(savedInstanceState)
		binding = ActivityMainBinding.inflate(layoutInflater)
		val view = binding.root
		setContentView(view)

		setOnCheckedChangeListener()
	}

	private fun setOnCheckedChangeListener() {
		binding.radioGroup.setOnCheckedChangeListener { group, checkedId ->
			val text = "You selected: " + if (R.id.radioMale == checkedId) "male" else "female"
			Toast.makeText(applicationContext, text, Toast.LENGTH_SHORT).show()
		}
	}
}

Now, run the application. We will get output as below –

Tutorialwing Android Radio Group Output

Different Attributes of Radio Group in XML

Now, we will see how to use different attributes of Android Radio Group using Kotlin to customise it –

Set Id of Radio Group

Many a time, we need id of View to access it in kotlin file or create ui relative to that view in xml file. So, we can set id of Radio Group using android:id attribute like below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        />

Here, we have set id of Radio Group as radioGroup_ID using android:id=”” attribute. So, if we need to reference this Radio Group, we need to use this id – radioGroup_ID.
Learn to Set ID of Radio Group Dynamically

Set Width of Radio Group

We use android:layout_width=”” attribute to set width of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        />

Width can be either “MATCH_PARENT” or “WRAP_CONTENT” or any fixed value (like 20dp, 30dp etc.).
Learn to Set Width of Radio Group Dynamically

Set Height of Radio Group

We use android:layout_height=”” attribute to set height of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

Height can be either “MATCH_PARENT” or “WRAP_CONTENT” or any fixed value.
Learn to Set Height of Radio Group Dynamically

Set Padding of Radio Group

We use android:padding=”” attribute to set padding of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        />

Here, we have set padding of 10dp in Radio Group using android:padding=”” attribute.
Learn to Set Padding of Radio Group Dynamically

Set Margin of Radio Group

We use android:layout_margin=”” attribute to set margin of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        />

Here, we have set margin of 10dp in Radio Group using android:layout_margin=”” attribute.
Learn to Set Margin of Radio Group Dynamically

Set Background of Radio Group

We use android:background=”” attribute to set background of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#ff0000"
        />

Here, we have set background of color #ff0000 in Radio Group using android:background=”” attribute.
Learn to Set Background of Radio Group Dynamically

Set Visibility of Radio Group

We use android:visibility=”” attribute to set visibility of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"
        />

Here, we have set visibility of Radio Group using android:visiblity=”” attribute. Visibility can be of three types – gone, visible and invisible
Learn to Set Visibility of Radio Group Dynamically

Set Text of Radio Group

We use android:text=”” attribute to set text of Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        />

Here, we have set text (“Hello Tutorialwing”) in Radio Group using android:text=”” attribute.
Similarly, we can set any text using this attribute.
Learn to Set Text of Radio Group Dynamically

Set Color of Text in Radio Group

We use android:textColor=”” attribute to set color of text in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:textColor="#ffffff"     
        />

Here, we have set color (#ffffff i.e. white) of text (“Hello Tutorialwing”) in Radio Group using android:textColor=”” attribute. Similarly, we can set any color using this attribute.
Learn to Set Color of Radio Group Dynamically

Set Gravity of Radio Group

We use android:gravity=”” attribute to set gravity of text in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:gravity="center_horizontal"
        />

Here, we have set gravity of text in Radio Group using android:gravity=”” attribute. Attribute value can be – “center_horizontal”, “center”, “center_vertical” etc.
Learn to Set Gravity of Radio Group Dynamically

Set Text in Uppercase, Lowercase

If we need to show text of Radio Group in uppercase or lowercase etc.

Set text in uppercase

We can use android:textAllCaps=”true” attribute to set text in uppercase. We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:textAllCaps="true"
        />

Attribute android:textAllCaps=”true” sets text in uppercase. So, HELLO TUTORIALWING is set in Radio Group.

By default, false is set in this attribute. So, Whatever value is written in android:text=”” attribute, it will be set as it is. For example,

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:textAllCaps="false"
        />

Above code will set Hello Tutorialwing to Radio Group.

How do we set text in lowercase?

Answer –

In xml file – write all the text in lowercase.

In kotlin file – take text as string. Then, convert it in lowercase. Then, set it to Radio Group.

Learn to Set Text in Uppercase or Lowercase Dynamically

Set Size of Text in Radio Group

We use android:textSize=”” attribute to set size of text in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:textSize="20sp"
        />

Here, we have set size of text in Radio Group using android:textSize=”” attribute.
Learn to Set Size of Text of Radio Group Dynamically

Set Style (Bold/italic) of Text in Radio Group

We use android:textStyle=”” attribute to set style (bold, italic etc.) of text in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:textStyle="bold"
        />

Here, we have set style of text in Radio Group using android:textStyle=”” attribute. This attribute can take bold, italic or normal.
Learn to Set Style of Text of Radio Group Dynamically

Set Letter Spacing of Text in Radio Group

We use android:letterSpacing=”” attribute to set spacing between letters of text in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:letterSpacing="1"
        />

Here, we have set spacing between letters of text in Radio Group using android:letterSpacing=”” attribute.
Learn to Set Letter Spacing of Text of Radio Group Dynamically

Set Typeface of Text in Radio Group

We use android:typeface=”” attribute to set typeface in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:typeface="sans"
        />

Here, we have set typeface of text in Radio Group using android:typeface=”” attribute. This attribute can take values – “sans”, “normal”, “monospace” or “normal”.
Learn to Set Typeface of Radio Group Dynamically

Set fontFamily of Text in Radio Group

We use android:fontFamily=”” attribute to set fontFamily of text in Radio Group.
We can do it as below –

    <RadioGroup
        android:id="@+id/radioGroup_ID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Tutorialwing"
        android:fontFamily="sans-serif"
        />

Here, we have set fontFamily (Here, sans-serif) of text in Radio Group using android:fontFamily=”sans-serif” attribute.

Till now, we have see how to use android Radio Group using Kotlin. We have also gone through different attributes of Radio Group to perform certain task. Let’s have a look at list of such attributes and it’s related task.

Different Attributes of Android Radio Group Widget

Below are the various attributes that are used to customise android Radio Group Widget. However, you can check the complete list of attributes of Radio Group in it’s official documentation site. Here, we are going to list some of the important attributes of this widget –

Some of the popular attributes of Radio Group inherited from LinearLayout are –

Sr.	XML Attributes	Description
1	android:baselineAligned	Set whether to align RadioGroup’s children baselines
2	android:divider	Set drawable to be used as a vertical divider between buttons
3	android:gravity	Defines how an object will be aligned within layout
4	android:orientation	Specifies how the object should be aligned within this layout. For example, horizontal or vertical etc.
5	android:weightSum	Specifies maximum weight sum

Some of the popular attributes of android Radio Group inherited from ViewGroup are –

Sr.	XML Attributes	Description
1	android:animationCache	Specifies whether layout animations should create a drawing cache for their children
2	android:clipChildren	Specifies whether a child is limited to draw inside of its bounds or not.
3	android:layoutMode	Specifies the layout mode of this ViewGroup.

Some of the popular attributes of android Radio Group inherited from View are –

Sr.	XML Attributes	Description
1	android:alpha	Specifies alpha of the view
2	android:background	Specifies background of the view
3	android:backgroundTint	Specifies background tint
4	android:clickable	Specifies whether view is clickable or not
5	android:id	Specifies id of the view. Note- Id must be unique within an xml file

We have seen different attributes of Radio Group and how to use it. If you wish to visit post to learn more about it

Thus, we have seen what is Radio Group, how can we use android Radio Group using Kotlin ? etc. We also went through different attributes of android Radio Group.