How to make an ImageView with rounded corners on Android App using Kotlin?

This example demonstrates how to make an ImageView with rounded corners on Android App 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.

Example

<?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"
   android:padding="4dp"
   tools:context=".MainActivity">
   <ImageView
      android:id="@+id/imageView"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />
</RelativeLayout>

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

Example

import android.graphics.*
import android.graphics.drawable.BitmapDrawable
import android.os.Bundle
import android.widget.ImageView
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      val imageView = findViewById(R.id.imageView)
      val bitmap = (resources.getDrawable(R.drawable.image) as BitmapDrawable).bitmap
      val imageRounded = Bitmap.createBitmap(bitmap.width, bitmap.height, bitmap.config)
      val canvas = Canvas(imageRounded)
      val paint = Paint()
      paint.isAntiAlias = true
      paint.shader = BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP)
      canvas.drawRoundRect(RectF(10F, 10F, bitmap.width.toFloat(), bitmap.height.toFloat()),
      200F, 200F, paint) // Round Image Corner 100 100 100 100
      imageView.setImageBitmap(imageRounded)
   }
}

Step 4 − Add the following code to androidManifest.xml

Example

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