Switch Between Activities in kotlin

1. Create a New Project

• Open Android Studio → New Project → Empty Activity.
• Let’s say it creates MainActivity by default.

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2. Add Another Activity

• Right-click on java folder → New → Activity → Empty Activity.
• Name it SecondActivity.
• Android will create:
  • SecondActivity.kt (Kotlin file)
  • activity_second.xml (layout file)

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3. Register the New Activity in AndroidManifest.xml

This step is usually done automatically, but confirm it’s there:

<activity android:name=".SecondActivity" />

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4. Design Layouts

Main Screen (with a Button)

📌 activity_main.xml

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    android:padding="20dp">

    <Button
        android:id="@+id/buttonSwitch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Go to Second Activity"/>
</LinearLayout>

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Second Screen

📌 activity_second.xml

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">

    <TextView
        android:id="@+id/textViewMessage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Welcome to Second Activity!"
        android:textSize="20sp"/>
</LinearLayout>

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5. Add Switching Logic

MainActivity (Start SecondActivity)

import android.content.Intent
import android.os.Bundle
import android.widget.Button
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val button = findViewById<Button>(R.id.buttonSwitch)

        button.setOnClickListener {
            // Create an intent to move to SecondActivity
            val intent = Intent(this, SecondActivity::class.java)
            startActivity(intent) // Switch activity
        }
    }
}

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SecondActivity (Optional Back Button)

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity

class SecondActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_second)

        // By default, Android adds a Back button in the top bar.
        // Or user can press phone's back button to return.
    }
}

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6. Running the App

• When you click “Go to Second Activity”, it will switch screens.
• Pressing the back button returns to MainActivity.

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🔑 Extra Tips

• To finish current activity when switching: startActivity(intent) finish() // closes MainActivity so user can’t go back
• To pass data along with switching: intent.putExtra("KEY", "Hello Second Activity")
• To receive data back from another activity → use startActivityForResult() (or ActivityResultLauncher in modern apps).

See the Complete video on YouTube