Android Toast in Kotlin

A Toast is a short alert message shown on the Android screen for a short interval of time. Android Toast is a short popup notification which is used to display information when we perform any operation in our app. In this tutorial, we shall not just limit ourselves by creating a lame toast but also do some user-interactive stuff. First, we shall create a screen with an Edit Text (Text box to take input) and a Button.

Step By Step Implementation to Demonstrate

Step 1: Create a new project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio.

Note: Select Kotlin as the programming language.

Step 2: Working with activity_main.xml

In the project window on the left side, navigate to app > res > layout > activity_main.xml.

Here we are going to add an Edit Text and a button. So, remove the hello word Text View in the XML. Now your XML should look like this.

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout  xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:app="http://schemas.android.com/apk/res-auto"  xmlns:tools="http://schemas.android.com/tools"  android:id="@+id/main"  android:layout_width="match_parent"  android:layout_height="match_parent"  tools:context=".MainActivity">  <EditText  android:id="@+id/editText"  android:layout_width="250dp"  android:layout_height="wrap_content"  android:hint="Message"  app:layout_constraintBottom_toTopOf="@+id/button"  app:layout_constraintEnd_toEndOf="parent"  app:layout_constraintHorizontal_bias="0.5"  app:layout_constraintStart_toStartOf="parent"  app:layout_constraintTop_toTopOf="parent"  app:layout_constraintVertical_chainStyle="packed" />  <Button  android:id="@+id/button"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_marginTop="32dp"  android:text="Toast"  app:layout_constraintBottom_toBottomOf="parent"  app:layout_constraintEnd_toEndOf="parent"  app:layout_constraintHorizontal_bias="0.5"  app:layout_constraintStart_toStartOf="parent"  app:layout_constraintTop_toBottomOf="@+id/editText" /> </androidx.constraintlayout.widget.ConstraintLayout> 

Design UI:

Step 3: Working with MainActivity.kt

Now, Let’s go to the Kotlin class file and make the toast happen. Open the Kotlin class file in app > java > {package-name} > MainActivity.kt

Here, editText is the object for EditText we have created in the Layout file. To get the contents of EditText we have used the text property and stored it in a variable message.

Making a Toast -

Toast.makeText(this, editText.text, Toast.LENGTH_LONG).show()

Toast.makeText() creates a toast and returns it and we should pass three parameters:

• context - The context to use. Usually your {@link android.app.Application}or {@link android.app.Activity} object.
• text - The text to show in String format.
• duration - How long to display the message. Either LENGTH_SHORT or LENGTH_LONG

Hiding the Android Soft Keyboard after clicking the Toast button to see a clear Toast

// (OPTIONAL) Function to hide the keyboard private fun hideKeyboard(activity: Activity) {  // Get the root view of the activity  val view: View = activity.findViewById(R.id.main)  // Get the InputMethodManager service  val imm = activity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager  // Hide the keyboard  imm.hideSoftInputFromWindow(view.windowToken, 0) } 

Add the above method to the main activity class and call it before making toast.

MainActivity.kt:

package org.geeksforgeeks.demo import android.app.Activity import android.content.Context import android.os.Bundle import android.view.View import android.view.inputmethod.InputMethodManager import android.widget.Button import android.widget.EditText import android.widget.Toast import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {  override fun onCreate(savedInstanceState: Bundle?) {  super.onCreate(savedInstanceState)  setContentView(R.layout.activity_main)  // Get reference to the button with the ID "toastButton"  val button: Button = findViewById(R.id.button)  // Set an OnClickListener for the button  button.setOnClickListener {  val editText: EditText = findViewById(R.id.editText)  // Create a toast message with the text from the EditText  Toast.makeText(this, editText.text, Toast.LENGTH_LONG).show()  // Call hideKeyboard function to hide the keyboard  hideKeyboard(this)  }  }  // (OPTIONAL) Function to hide the keyboard  private fun hideKeyboard(activity: Activity) {  // Get the root view of the activity  val view: View = activity.findViewById(R.id.main)  // Get the InputMethodManager service  val imm = activity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager  // Hide the keyboard  imm.hideSoftInputFromWindow(view.windowToken, 0)  } } 

Output: