How to get the screen DPI programmatically in Android using Kotlin?

This example demonstrates how to get the screen DPI programmatically 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.

Example

<?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"
   tools:context=".MainActivity">
<TextView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_centerHorizontal="true"
   android:layout_marginTop="50dp"
   android:text="Tutorials Point"
   android:textAlignment="center"
   android:textColor="@android:color/holo_green_dark"
   android:textSize="32sp"
   android:textStyle="bold" />
<TextView
   android:id="@+id/textView"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignParentTop="true"
   android:layout_centerHorizontal="true"
   android:layout_marginTop="180dp"
   android:text="Show Density Here"
   android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
   android:id="@+id/btnShowDensity"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_below="@+id/textView"
   android:layout_centerHorizontal="true"
   android:layout_marginTop="20dp"
   android:text="Click here to Find screen density" />
</RelativeLayout>

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

import android.app.Activity
import android.os.Bundle
import android.util.DisplayMetrics
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
   lateinit var button: Button
   lateinit var textView: TextView
   var value = 0f
   lateinit var displayMetrics: DisplayMetrics
   var activity: Activity? = null
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      button = findViewById(R.id.btnShowDensity)
      textView = findViewById(R.id.textView)
      activity = this
      button.setOnClickListener {
         displayMetrics = DisplayMetrics()
         activity!!.windowManager.defaultDisplay.getMetrics(displayMetrics)
         value = resources.displayMetrics.density
         textView.text = "Screen Density = $value"
      }
   }
}

Step 4 − 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="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