How do I send an object from one Android Activity to another using Intents in Kotlin?

This example demonstrates how to send an object from one Android Activity to another using Intents in 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="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="70dp"
   android:background="#008080"
   android:padding="5dp"
   android:text="TutorialsPoint"
   android:textColor="#fff"
   android:textSize="24sp"
   android:textStyle="bold" />
   <EditText
      android:id="@+id/editText"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:hint="Enter your Message" />
<Button
   android:id="@+id/btnSendObj"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_below="@id/editText"
   android:layout_centerInParent="true"
   android:layout_marginTop="15dp"
   android:text="Send Obj to 2nd Activity" />
</RelativeLayout>

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

import android.content.Intent
import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import androidx.appcompat.app.AppCompatActivity
import java.io.Serializable
class MainActivity : AppCompatActivity() {
   lateinit var editText: EditText
   lateinit var button: Button
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      editText = findViewById(R.id.editText)
      button = findViewById(R.id.btnSendObj)
      button.setOnClickListener {
         val intent = Intent(this@MainActivity, SecondActivity::class.java)
         val message = Message()
         message.setMessage(editText.text.toString())
         intent.putExtra("message", message)
         startActivity(intent)
      }
   }
}
class Message : Serializable {
   private var message: String? = null
   override fun toString(): String {
      return "$message"
   }
   fun setMessage(message: String?) {
      this.message = message
   }
   companion object {
      private const val serialVersionUID = 1L
   }
}

Step 4 − Create a New empty activity and add the following code −

activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent">
   <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="70dp"
      android:background="#008080"
      android:padding="5dp"
      android:text="TutorialsPoint"
      android:textColor="#fff"
      android:textSize="24sp"
      android:textStyle="bold" />
   <TextView
      android:textAlignment="center"
      android:id="@+id/textView"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:textColor="@android:color/holo_purple"
      android:textSize="24sp"
      android:textStyle="bold" />
</RelativeLayout>

SecondActivity.kt

import android.os.Bundle
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
class SecondActivity : AppCompatActivity() {
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_second)
      title = "KotlinApp"
      val textView:TextView = findViewById(R.id.textView);
      val intent = intent
      val message = intent.getSerializableExtra("message") as Message?
      textView.text = "$message"
   }
}

Step 5 − 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.