SmsManager in Android using Jetpack Compose

Many times while building an android application we have to add a feature through which users will be able to directly send SMS from our android application. So in this article, we will take a look at How to send a text message over a phone using SMS Manager in Android using Jetpack Compose. A sample video is given below to get an idea about what we are going to do in this article.

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.os.Build
import android.os.Bundle
import android.telephony.SmsManager
import android.widget.Space
import android.widget.Toast
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.res.colorResource
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontFamily
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.input.KeyboardCapitalization
import androidx.compose.ui.text.input.KeyboardType
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.TextUnit
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import com.example.newcanaryproject.ui.theme.NewCanaryProjectTheme
import com.example.newcanaryproject.ui.theme.greenColor
import com.github.skydoves.colorpicker.compose.*

class MainActivity : ComponentActivity() {

    @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
                        smsUI(context = LocalContext.current)
                    }
                }
            }
        }
    }
}

@Composable
fun smsUI(context: Context) {
    // on below line creating variable for
    // service status and button value.
    val phoneNumber = remember {
        mutableStateOf("")
    }
    val message = 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 = "SMS Manager in Android",
            // 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 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 ar adding single line to it.
            singleLine = true,
        )
        // on below line we are adding a spacer.
        Spacer(modifier = Modifier.height(20.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))
        // on below line adding a button to send SMS
        Button(onClick = {
            // on below line running a try catch block for sending sms.
            try {
                // on below line initializing sms manager.
                val smsManager: SmsManager = SmsManager.getDefault()
                // on below line sending sms
                smsManager.sendTextMessage(phoneNumber.value, null, message.value, null, null)
                // on below line displaying
                // toast message as sms send.
                Toast.makeText(
                    context,
                    "Message Sent",
                    Toast.LENGTH_LONG
                ).show()
            } catch (e: Exception) {
                // on below line handling error and
                // displaying toast message.
                Toast.makeText(
                    context,
                    "Error : " + e.message,
                    Toast.LENGTH_LONG
                ).show()
            }
        }) {
            // on below line creating a text for our button.
            Text(
                // on below line adding a text ,
                // padding, color and font size.
                text = "Send SMS",
                modifier = Modifier.padding(10.dp),
                color = Color.White,
                fontSize = 15.sp
            )
        }
    }
}

Step 4: Adding permissions in AndroidManifest.xml

Navigate to AndroidManifest.xml and add the below permission to it for sending SMS.

XML

<uses-permission android:name="android.permission.SEND_SMS"/>

Now run your application to see the output of it. 

Output:

Note: We are sending SMS to a sample phone number and that’s why it is displaying as failed in the SMS application. If we enter the actual number to whom we have to send SMS it will be sent to that number.