Kotlin code Send SMS from within App without using default app - kotlin

Question

I am trying to build an app whereby the user clicks a submit button which will send the contents of their input via SMS to a predefined number. Being very new to Kotlin, I have been helped with the code to send the data via SMS, however it opens up the default messaging app and the user has to interact with the messaging app and then navigate back to my app. What I would like is for this to happen in the background and send directly from my app. The code is below...Any help greatly appreciated, Many thanks
class SecondActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_second)
val backbut = findViewById<Button>(R.id.backbut)
backbut.setOnClickListener {
val intent = Intent(this, MainActivity::class.java)
startActivity(intent)
}
var spinner: Spinner? = null
spinner = this.spinner
val sub1: Button = findViewById<Button>(R.id.sub1)
sub1.setOnClickListener {
val cust: String = cust.text.toString()
val reg: String = reg.text.toString()
val pal: String = pal.text.toString()
val cont:String = cont.text.toString()
val data: String =
"CUSTOMER : ".plus(cust).plus("\n").plus("CONTAINER : ").plus(cont).plus("\n").plus("VEH
REG : ").plus(reg).plus("\n").plus("PALLETS : ")
.plus(pal)
startActivity(getSendSmsIntent("1234567", data))
}
}
// textview_selected!!.text = "Selected : "+ Spinner [position]
private fun getSendSmsIntent(phoneNumber: String, content: String?): Intent? {
val uri = Uri.parse("smsto:$phoneNumber")
val intent = Intent(Intent.ACTION_SENDTO, uri)
intent.putExtra("sms_body", content)
return getIntent(intent, true)
}
private fun getIntent(intent: Intent, isNewTask: Boolean): Intent? {
return if (isNewTask) intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK) else intent
}
}

Answer 1

After reading the documentation, I think you can achieve your needs using the following code :
private fun sendSMS(phoneNumber: String, message: String) {
val sentPI: PendingIntent = PendingIntent.getBroadcast(this, 0, Intent("SMS_SENT"), 0)
SmsManager.getDefault().sendTextMessage(phoneNumber, null, message, sentPI, null)
}
Add this permission to your AndroidManifest and make sure it's granted :
<uses-permission android:name="android.permission.SEND_SMS" />
Call sendSMS method as follows :
sendSMS("[phone]", "Some text here")
Screenshot :