Hello Readers! In this post, we are going to learn about android switch using kotlin in any android application. We will also go through different attributes of Switch widget that can be used to customise it.

Output

Tutorialwing Android Switch Output

Getting Started

Android Switch can be defined as below –

Android Switch is a two-state toggle widget that can select between two options (ON or OFF). The user can drag and drop thumb to select between two options or it can simply tap to toggle the state.

Different Attributes of Android Switch Widget

Some of the popular attributes of Switch widget are –

Some of the popular attributes of android Switch widget inherited from Compound Button are –

Some of the popular attributes of android Switch inherited from TextView are –

Some of the popular attributes of android Switch inherited from View are –

Example of Android Switch Using Kotlin

At first, we will create android application. Then, we will use switch widget in the application.

1. Creating New Project in Kotlin

Follow steps below to create new project. Please ignore the steps if you have already created the project.

Since we have a new application, we will modify xml and other file to use switch using kotlin in the application.

2. Modify values folder

No values folders have been modified. So, we are not going to mention them here.

3. Use Switch Widget in xml file

Open src/main/res/layout/activity_main.xml file and add below code into 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:gravity="center"
	android:orientation="vertical">

	<Switch
		android:id="@+id/switch1"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:text="OFF"/>

</LinearLayout>

In activity_main.xml file, we have defined Switch widget. Now, we will access this Switch using kotlin file in the application.

4. Access Switch Using Kotlin file

Open src/main/java/com.tutorialwing.aswitch/MainActivity.kt file and add below code into it.

package com.tutorialwing.aswitch

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.Switch
import android.widget.Toast

class MainActivity : AppCompatActivity() {

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

        val sw = findViewById<Switch>(R.id.switch1)
        sw?.setOnCheckedChangeListener({ _, isChecked ->
            val msg = if (isChecked) "ON" else "OFF"
            Toast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show()
            sw.text = msg
        })
    }
}

In MainActivity.kt file, we have accessed Switch widget defined in xml file. Then, we have set a checked change listener to show a toast message whenever checked state is changed.

Since AndroidManifest.xml file is very important in android application, we are also going to see the content inside this file.

AndroidManifest.xml file

Code inside main/AndroidManifest.xml file is as below.

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.tutorialwing.aswitch"
		  xmlns:android="http://schemas.android.com/apk/res/android">

	<application
		android:allowBackup="true"
		android:icon="@mipmap/ic_launcher"
		android:label="@string/app_name"
		android:roundIcon="@mipmap/ic_launcher_round"
		android:supportsRtl="true"
		android:theme="@style/AppTheme">
		<activity android:name=".MainActivity">
			<intent-filter>
				<action android:name="android.intent.action.MAIN"/>

				<category android:name="android.intent.category.LAUNCHER"/>
			</intent-filter>
		</activity>
	</application>

</manifest>

When we run the program, we will get output as shown above.

That’s end of our tutorial on Android Switch using Kotlin.