How to convert pixels to dp in an Android App using Kotlin?

This example demonstrates how to convert pixels to dp in an 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.

<?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">    <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" />    <Button       android:id="@+id/button"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_centerInParent="true"       android:text="Convert Pixels to DPs" />    <TextView       android:id="@+id/textView"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_below="@id/button"       android:textAlignment="center"       android:textColor="#ff0000"       android:textSize="24sp"       android:textStyle="bold" /> </RelativeLayout>

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

import android.content.Context import android.os.Bundle import android.widget.Button import android.widget.TextView import androidx.appcompat.app.AppCompatActivity import kotlin.math.roundToInt class MainActivity : AppCompatActivity() {    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = "KotlinApp"       val button = findViewById<Button>(R.id.button)       val textView = findViewById<TextView>(R.id.textView)       button.setOnClickListener {          val pixelsOne = 38          val pixelsTwo = 43          val context: Context = applicationContext          textView.text = """          Convert Pixels to integer DPs value:          ${pixelsOne}pixels = ${getDPsFromPixels(context, pixelsOne)}dp          ${pixelsTwo}pixels = ${getDPsFromPixels(context, pixelsTwo)}          """.trimIndent()          textView.text = (textView.text.toString() + "Convert Pixels to perfect DPs value: 
"          + pixelsOne + "pixels = " + getActualDPsFromPixels(context, pixelsOne)          + "dp
" + pixelsOne + "pixels = " + getActualDPsFromPixels(context, pixelsOne))       }    }    private fun getDPsFromPixels(context: Context, pixels: Int): Int {       val resources = context.resources       return (pixels / (resources.displayMetrics.densityDpi / 160f)).roundToInt()    }    private fun getActualDPsFromPixels(context: Context, pixels: Int): Float {       val resources = context.resources       return pixels / (resources.displayMetrics.densityDpi / 160f)    } }

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