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How to add Radio Buttons in an Android Application?

Adding radio buttons to an Android application allows you to present a list of options where the user can select only one option from the set. To group radio buttons and ensure that only one can be selected at a time, you should use the RadioGroup widget.

Here's a step-by-step guide to add radio buttons in an Android application:

1. Create a new XML Layout:

In your activity_main.xml (or any other XML layout file), add a RadioGroup and some RadioButton elements inside it:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    android:orientation="vertical">

    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <RadioButton
            android:id="@+id/radioOption1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Option 1" />

        <RadioButton
            android:id="@+id/radioOption2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Option 2" />

        <RadioButton
            android:id="@+id/radioOption3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Option 3" />

    </RadioGroup>

    <Button
        android:id="@+id/submitButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Submit" />

</LinearLayout>

2. Add Logic in Your Activity:

In your MainActivity.kt:

import android.os.Bundle
import android.widget.Button
import android.widget.RadioButton
import android.widget.RadioGroup
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val radioGroup: RadioGroup = findViewById(R.id.radioGroup)
        val submitButton: Button = findViewById(R.id.submitButton)

        submitButton.setOnClickListener {
            val selectedId = radioGroup.checkedRadioButtonId
            val radioButton: RadioButton = findViewById(selectedId)
            Toast.makeText(this, "Selected: ${radioButton.text}", Toast.LENGTH_SHORT).show()
        }
    }
}

In the above Kotlin code:

We get a reference to our RadioGroup and the submit Button.
When the submit button is clicked, we find out which RadioButton is selected within the RadioGroup by calling checkedRadioButtonId on the RadioGroup.
We then get a reference to that RadioButton and display its text using a Toast.

3. Run Your App:

Now, when you run your app, you'll see the radio buttons. When you click the submit button, the app will display a toast message with the selected radio button's text.

Adding Radio Buttons in Android Studio:

Include a RadioButton in your XML layout:

<RadioButton
    android:id="@+id/radioButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Radio Button"/>

Using RadioGroup with Radio Buttons in Android:

Group RadioButtons using a RadioGroup to ensure only one can be selected:

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

    <RadioButton
        android:id="@+id/radioButton1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Option 1"/>

    <RadioButton
        android:id="@+id/radioButton2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Option 2"/>
</RadioGroup>

Customizing Radio Buttons in Android example:

Customize the appearance of RadioButtons using XML attributes or styles:

<RadioButton
    android:id="@+id/radioButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Customized Radio Button"
    android:textSize="18sp"
    android:textColor="@color/customColor"/>

Handling Radio Button selection in Android:

Set up a listener to handle radio button selection:

val radioGroup = findViewById<RadioGroup>(R.id.radioGroup)

radioGroup.setOnCheckedChangeListener { group, checkedId ->
    // Handle radio button selection
    val radioButton: RadioButton = findViewById(checkedId)
    // Do something with radioButton
}

Setting up Radio Button groups in Android app:

Use RadioGroup to group related RadioButtons:

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

    <!-- RadioButtons go here -->

</RadioGroup>

Styling and theming Radio Buttons in Android:

Apply styles and themes to RadioButtons in your styles.xml:

<style name="RadioButtonStyle" parent="Widget.AppCompat.CompoundButton.RadioButton">
    <!-- Custom styling here -->
</style>

Apply the style to your RadioButton:

<RadioButton
    android:id="@+id/radioButton"
    style="@style/RadioButtonStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Styled Radio Button"/>

Listening to Radio Button changes in Android:

Use the OnCheckedChangeListener to listen for changes:

val radioGroup = findViewById<RadioGroup>(R.id.radioGroup)

radioGroup.setOnCheckedChangeListener { group, checkedId ->
    // Handle radio button selection
}

RadioButton XML attributes in Android:

Customize RadioButtons using various XML attributes such as android:checked, android:text, android:textColor, etc.

<RadioButton
    android:id="@+id/radioButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Custom Radio Button"
    android:checked="true"
    android:textColor="@color/customColor"/>