Send Message on WhatsApp using Android Jetpack Compose

Many times in android applications we want to provide functionality through which we should be able to send the message directly from our mobile application on WhatsApp. In this article, we will take a look at How to send message from an android application to WhatsApp using Jetpack Compose.

Step by Step Implementation

Step 1: Create a New Project in Android Studio

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. While choosing the template, select Empty Compose Activity. If you do not find this template, try upgrading the Android Studio to the latest version. We demonstrated the application in Kotlin, so make sure you select Kotlin as the primary language while creating a New Project.

Step 2: Adding a new color to the Color.kt file

Navigate to app > java > your app’s package name > ui.theme > Color.kt file and add the below code to it.

Kotlin

package com.example.newcanaryproject.ui.theme

import androidx.compose.ui.graphics.Color

val Purple200 = Color(0xFF0F9D58)
val Purple500 = Color(0xFF0F9D58)
val Purple700 = Color(0xFF3700B3)
val Teal200 = Color(0xFF03DAC5)

// on below line we are adding different colors.
val greenColor = Color(0xFF0F9D58)

Step 3: Working with the MainActivity.kt file

Go to the MainActivity.kt file and refer to the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.

Kotlin

package com.example.newcanaryproject

import android.content.Context
import android.content.Intent
import android.net.Uri
import android.os.Build
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.annotation.RequiresApi
import androidx.compose.foundation.layout.*
import androidx.compose.material.*
import androidx.compose.runtime.Composable
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.core.content.ContextCompat.startActivity
import com.example.newcanaryproject.ui.theme.NewCanaryProjectTheme
import com.example.newcanaryproject.ui.theme.greenColor


class MainActivity : ComponentActivity() {

    var contactName: String = ""
    var contactNumber: String = ""

    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            NewCanaryProjectTheme {
                // on below line we are specifying background color for our application
                Surface(
                    // on below line we are specifying modifier and color for our app
                    modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background
                ) {

                    // on the below line we are specifying
                    // the theme as the scaffold.
                    Scaffold(

                        // in scaffold we are specifying the top bar.
                        topBar = {

                            // inside top bar we are specifying background color.
                            TopAppBar(backgroundColor = greenColor,

                                // along with that we are specifying
                                // title for our top bar.
                                title = {

                                    // in the top bar we are
                                    // specifying tile as a text
                                    Text(
                                        // on below line we are specifying
                                        // text to display in top app bar.
                                        text = "GFG",

                                        // on below line we are specifying
                                        // modifier to fill max width.
                                        modifier = Modifier.fillMaxWidth(),

                                        // on below line we are specifying
                                        // text alignment.
                                        textAlign = TextAlign.Center,

                                        // on below line we are specifying
                                        // color for our text.
                                        color = Color.White
                                    )
                                })
                        }) {
                        // on below line we are calling connection information
                        // method to display UI
                        sendWhatsAppMessage(context = LocalContext.current)
                    }
                }
            }
        }
    }
}

// on below line creating a
// method to send whatsapp message.
@Composable
fun sendWhatsAppMessage(context: Context) {

    // on below line creating a variable
    // for phone number and message.
    val message = remember {
        mutableStateOf("")
    }
    val phoneNumber = remember {
        mutableStateOf("")
    }

    // on below line we are creating a column,
    Column(
        // on below line we are adding a modifier to it,
        modifier = Modifier
            .fillMaxSize()
            // on below line we are adding a padding.
            .padding(all = 30.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        // on below line we are adding a text for heading.
        Text(
            // on below line we are specifying text
            text = "Send SMS to WhatsApp",
            // on below line we are
            // specifying text color,
            // font size and font weight
            color = greenColor,
            fontSize = 20.sp,
            fontWeight = FontWeight.Bold
        )

        // on below line we are creating a
          // text field for our phone number.
        TextField(
            // on below line we are specifying
            // value for our email text field.
            value = phoneNumber.value,
            // on below line we are adding on value
            // change for text field.
            onValueChange = { phoneNumber.value = it },
            // on below line we are adding place holder as text
            // as "Enter your email"
            placeholder = { Text(text = "Enter your whatsapp phone number") },
            // on below line we are adding modifier to it
            // and adding padding to it and filling max width
            modifier = Modifier
                .padding(16.dp)
                .fillMaxWidth(),
            // on below line we are adding text style
            // specifying color and font size to it.
            textStyle = TextStyle(color = Color.Black, fontSize = 15.sp),
            // on below line we are adding single line to it.
            singleLine = true,
        )

        // on below line we are adding a spacer.
        Spacer(modifier = Modifier.height(10.dp))

        // on below line we are creating a text
          // field for our message number.
        TextField(
            // on below line we are specifying
            // value for our message text field.
            value = message.value,
            // on below line we are adding on value
            // change for text field.
            onValueChange = { message.value = it },
            // on below line we are adding place holder
            // as text as "Enter your email"
            placeholder = { Text(text = "Enter your message") },
            // on below line we are adding modifier to it
            // and adding padding to it and filling max width
            modifier = Modifier
                .padding(16.dp)
                .fillMaxWidth(),
            // on below line we are adding text style
            // specifying color and font size to it.
            textStyle = TextStyle(color = Color.Black, fontSize = 15.sp),
            // on below line we are adding single line to it.
            singleLine = true,
        )
        // on below line adding a spacer.
        Spacer(modifier = Modifier.height(20.dp))

        Button(
            onClick = {
                // on below line we are starting activity
                // to send the sms from whatsapp.
                context.startActivity(
                    // on below line we are opening the intent.
                    Intent(
                        // on below line we are calling
                        // uri to parse the data
                        Intent.ACTION_VIEW,
                        Uri.parse(
                            // on below line we are passing uri,
                            // message and whats app phone number.
                            java.lang.String.format(
                                "https://api.whatsapp.com/send?phone=%s&text=%s",
                                phoneNumber.value,
                                message.value
                            )
                        )
                    )
                )

            },
            // on below line adding
            // a modifier for our button.
            modifier = Modifier
                .fillMaxWidth()
                .padding(10.dp)
        ) {
            // on below line adding a text for our button.
            Text(text = "Send Message on WhatsApp")
        }
    }
}

Now run your application to see the output of it. 

Output: