How to determine the size of an Android view at runtime using Kotlin?

This example demonstrates how to determine the size of an Android view at runtime 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="https://schemas.android.com/apk/res/android"
   xmlns:tools="https://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical"
   android:padding="8dp"
   tools:context=".MainActivity">
   <ImageView
      android:id="@+id/imageView"
      android:layout_width="match_parent"
      android:layout_height="500dp"
      android:layout_gravity="center"
      android:src="@drawable/image" />
   <TextView
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@id/imageView"
      android:layout_centerInParent="true"
      android:layout_marginTop="20sp"
      android:textColor="@android:color/background_dark"
      android:textSize="16sp"
      android:textStyle="bold" />
</RelativeLayout>

Step 3 − Copy and paste an image (.png/.jpg/.jpeg) into res/drawable

Step 4 − Add the following code to src/MainActivity.kt

import android.os.Bundle
import android.view.View
import android.view.ViewTreeObserver.OnGlobalLayoutListener
import android.widget.ImageView
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
   private lateinit var imageView: ImageView
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      imageView = findViewById(R.id.imageView)
      imageView.viewTreeObserver.addOnGlobalLayoutListener(GetViewSize())
   }
   internal inner class GetViewSize : OnGlobalLayoutListener {
      override fun onGlobalLayout() {
         val view = findViewById<View>(R.id.imageView)
         val x = view.width.toString()
         val y = view.height.toString()
         (findViewById<View>(R.id.textView) as TextView).text = String.format("Width %s, Height: %s", x, y)
      }
   }
}

Step 5 − Add the following code to androidManifest.xml

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