How to send message on WhatsApp in Android using Kotlin

Note: To view how to do this in Java, please refer How to send message on WhatsApp in Android using Java.

<LinearLayout 
      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:layout_width="match_parent"
      android:layout_height="match_parent"
      tools:context=".MainActivity"
      android:orientation="vertical">

  <!--EditText to take message input from user-->
  <EditText
      android:id="@+id/message"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_margin="16dp"
      android:hint="Enter you message here"
      android:lines="8"
      android:inputType="textMultiLine"
      android:gravity="left|top"
      />

  <!--Button to send message on Whatsapp-->
  <Button
      android:id="@+id/submit"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center_horizontal"
      android:text="Submit"
      android:background="@color/colorPrimary"
      android:textColor="@android:color/white"/>
</LinearLayout>

• Take the reference of EditText and Button in Kotlin file. References are taken using the ids with the help of findViewById() method. Taking reference of EditText

  // Referencing the Edit Text val messageEditText = findViewById<EditText>(R.id.message)

  Similarly taking reference of button

  // Referencing the button val submit = findViewById<Button>(R.id.submit)

• Write a function to send message to WhatsApp. Create an intent with ACTION_SEND and specify the whatsapp package name to this so that it opens directly. com.whatsapp is the package name for official WhatsApp application. Kotlin

  fun sendMessage(message:String){
  
           // Creating intent with action send
           val intent = Intent(Intent.ACTION_SEND)
  
           // Setting Intent type
           intent.type = "text/plain"
  
           // Setting whatsapp package name
           intent.setPackage("com.whatsapp")
  
           // Give your message here
           intent.putExtra(Intent.EXTRA_TEXT, message)
  
           // Checking whether whatsapp is installed or not
           if (intent.resolveActivity(packageManager) == null) {
               Toast.makeText(this, 
                              "Please install whatsapp first.", 
                              Toast.LENGTH_SHORT).show()
               return
           }
  
           // Starting Whatsapp
           startActivity(intent)
       }
  

• Set the click listener using setOnClickListener on the button to send the message. Get the text entered by the user and call the function to send message on whatsapp. Kotlin

          // Setting on click listener
          submit.setOnClickListener {
              val message = messageEditText.text.toString()
  
          // Calling the function
              sendMessage(message);
          }
  

package com.gfg

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

class MainActivity : AppCompatActivity() {

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

        // Referencing the Edit Text
        val messageEditText = findViewById<EditText>(R.id.message)

        // Referencing the button
        val submit = findViewById<Button>(R.id.submit)

        // Setting on click listener
        submit.setOnClickListener {
            val message = messageEditText.text.toString()

        // Calling the function
        sendMessage(message);
        }
    }

    fun sendMessage(message: String) {

        // Creating intent with action send
        val intent = Intent(Intent.ACTION_SEND)

        // Setting Intent type
        intent.type = "text/plain"

        // Setting whatsapp package name
        intent.setPackage("com.whatsapp")

        // Give your message here
        intent.putExtra(Intent.EXTRA_TEXT, message)

        // Checking whether whatsapp is installed or not
        if (intent.resolveActivity(packageManager) == null) {
            Toast.makeText(this, 
                           "Please install whatsapp first.", 
                           Toast.LENGTH_SHORT).show()
            return
        }

        // Starting Whatsapp
        startActivity(intent)
    }
}