How to get the ActionBar height in Android using Kotlin?

This example demonstrates how to get the ActionBar height in Android using Kotlin.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <androidx.appcompat.widget.Toolbar
      android:id="@+id/actionBarSize"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:background="@color/colorAccent"
      android:theme="@style/ThemeOverlay.AppCompat.Dark">
   </androidx.appcompat.widget.Toolbar>
   <Button
      android:id="@+id/btnGetHeight"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:text="Get Action Bar height" />
   <TextView
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@id/btnGetHeight"
      android:layout_centerInParent="true"
      android:layout_marginTop="15dp"
      android:textSize="16sp"
      android:textStyle="bold" />
</RelativeLayout>

Step 3 − Add the following code to src/MainActivity.kt

import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.Toolbar
class MainActivity : AppCompatActivity() {
   lateinit var toolbar: Toolbar
   lateinit var button: Button
   lateinit var textView: TextView
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      toolbar = findViewById(R.id.actionBarSize)
      toolbar.title = "MyActionBar"
      supportActionBar
      textView = findViewById(R.id.textView)
      button = findViewById(R.id.btnGetHeight)
      button.setOnClickListener {
         val height = toolbar.height
         textView.text = "ActionBar Height: $height pixels"
      }
   }
}

Step 4 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.q11">
   <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>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen.