This example demonstrates how to convert a Base64 string into a BitMap image in 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"?> <LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center_horizontal" android:orientation="vertical" android:padding="16dp"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Base64 string into a BitMap image in Android App" android:textColor="@android:color/holo_blue_dark" android:textSize="16sp" android:textStyle="bold|italic" /> <ImageView android:layout_marginTop="8dp" android:id="@+id/imageView" android:layout_width="match_parent" android:layout_height="match_parent" /> </LinearLayout>
Step 3 − Add the following code to src/MainActivity.kt
import android.graphics.Bitmap import android.graphics.BitmapFactory import android.os.Bundle import android.util.Base64 import android.widget.ImageView import androidx.appcompat.app.AppCompatActivity import java.io.ByteArrayOutputStream class MainActivity : AppCompatActivity() { lateinit var imageView: ImageView override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) imageView = findViewById(R.id.imageView) val byteArrayOutputStream = ByteArrayOutputStream() val bitmap = BitmapFactory.decodeResource(resources, R.drawable.image) bitmap.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream) var imageBytes: ByteArray = byteArrayOutputStream.toByteArray() val imageString: String = Base64.encodeToString(imageBytes, Base64.DEFAULT) imageBytes = Base64.decode(imageString, Base64.DEFAULT) val decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size) imageView.setImageBitmap(decodedImage) } }
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="app.com.q1"> <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