Android – Listen For Incoming SMS Messages

Question

I am trying to create an application for monitoring incoming SMS messages, and launch a program via incoming SMS, also it should read the content from the SMS.

Workf

Answer 1

If someone referring how to do the same feature (reading OTP using received SMS) on Xamarin Android like me :

1. Add this code to your AndroidManifest.xml file :

2. Then create your BroadcastReveiver class in your Android Project.

   [BroadcastReceiver(Enabled = true)] [IntentFilter(new[] { "android.provider.Telephony.SMS_RECEIVED" }, Priority = (int)IntentFilterPriority.HighPriority)] 
   public class BroadcastReveiverOTP : BroadcastReceiver {
           public static readonly string INTENT_ACTION = "android.provider.Telephony.SMS_RECEIVED";
   
           protected string message, address = string.Empty;
   
           public override void OnReceive(Context context, Intent intent)
           {
               if (intent.HasExtra("pdus"))
               {
                   var smsArray = (Java.Lang.Object[])intent.Extras.Get("pdus");
                   foreach (var item in smsArray)
                   {
                       var sms = SmsMessage.CreateFromPdu((byte[])item);
                       address = sms.OriginatingAddress;
                       if (address.Equals("NotifyDEMO"))
                       {
                           message = sms.MessageBody;
                           string[] pin = message.Split(' ');
                           if (!string.IsNullOrWhiteSpace(pin[0]))
                           { 
                                   // NOTE : Here I'm passing received OTP to Portable Project using MessagingCenter. So I can display the OTP in the relevant entry field.
                                   MessagingCenter.Send(this,MessengerKeys.OnBroadcastReceived, pin[0]);
                           }
                           }
                   }
               }
           }
   }
   

3. Register this BroadcastReceiver class in your MainActivity class on Android Project:

   public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity {
   
           // Initialize your class
           private BroadcastReveiverOTP _receiver = new BroadcastReveiverOTP ();
   
           protected override void OnCreate(Bundle bundle) { 
                   base.OnCreate(bundle);
   
                   global::Xamarin.Forms.Forms.Init(this, bundle);
                   LoadApplication(new App());
   
                   // Register your receiver :  RegisterReceiver(_receiver, new IntentFilter("android.provider.Telephony.SMS_RECEIVED"));
   
           }
   }