How to call a method after a delay in Android Kotlin?

This example demonstrates how to call a method after a delay in Android 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"    android:padding="16sp"    tools:context=".MainActivity">    <TextView       android:id="@+id/textViewTitle"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_centerHorizontal="true"       android:layout_marginTop="50dp"       android:padding="8dp"       android:text="Tutorials Point"       android:textColor="@color/colorPrimaryDark"       android:textSize="48sp"       android:textStyle="bold" />    <TextView       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_below="@id/textViewTitle"       android:layout_centerInParent="true"       android:text="Wait for the Toast to display."       android:textColor="@android:color/background_dark"       android:textSize="24sp"       android:textStyle="bold" />    <TextView       android:id="@+id/textView"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_centerInParent="true"       android:textColor="@android:color/holo_blue_dark"       android:textSize="24sp"       android:textStyle="bold" /> </RelativeLayout>

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

Example

import android.os.Bundle import android.os.Handler import android.widget.TextView import android.widget.Toast import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var textView: TextView    private val string = "Delay by 5 seconds"    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = "KotlinApp"       textView = findViewById(R.id.textView)       val handler = Handler()       handler.postDelayed({ testToast() }, 5000)    }    private fun testToast() {       Toast.makeText(this, "This method is called after a delay!", Toast.LENGTH_SHORT).show()       textView.text = string    } }

Step 4 − Add the following code to androidManifest.xml

Example

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.kotlipapp">    <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 −