How to work with Camera in an Android App using Kotlin?

Kotlin AndroidApps/ApplicationsMobile Development

This example demonstrates how to work with Camera 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.

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"
   tools:context=".MainActivity">
<Button
   android:id="@+id/button"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignParentBottom="true"
   android:layout_centerHorizontal="true"
   android:text="Take a Photo" />
<ImageView
   android:id="@+id/imageView"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:layout_above="@+id/button"
   android:layout_alignParentTop="true" />
</RelativeLayout>

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

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import android.graphics.Bitmap
import android.os.Bundle
import android.provider.MediaStore
import android.widget.Button
import android.widget.ImageView
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
class MainActivity : AppCompatActivity() {
   private val cameraRequest = 1888
   lateinit var imageView: ImageView
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      if (ContextCompat.checkSelfPermission(applicationContext, Manifest.permission.CAMERA)
      == PackageManager.PERMISSION_DENIED)
      ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), cameraRequest)
      imageView = findViewById(R.id.imageView)
      val photoButton: Button = findViewById(R.id.button)
      photoButton.setOnClickListener {
         val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
         startActivityForResult(cameraIntent, cameraRequest)
      }
   }
   override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
      super.onActivityResult(requestCode, resultCode, data)
      if (requestCode == cameraRequest) {
         val photo: Bitmap = data?.extras?.get("data") as Bitmap
         imageView.setImageBitmap(photo)
      }
   }
}

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

raja
Published on 21-Jul-2020 12:12:55
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