BroadcastReceiver.txt

//1- BroadcastReceiver Class
   
[BroadcastReceiver(Exported = true, Label = "SMS Receiver")]
    [IntentFilter(new string[] { "android.provider.Telephony.SMS_RECEIVED","com.alr.text" })]
    public class SMSReceiver : Android.Content.BroadcastReceiver
    {
        private const string Tag = "SMSBroadcastReceiver";
        private const string IntentAction = "android.provider.Telephony.SMS_RECEIVED";

        public override void OnReceive(Context context, Intent intent)
        {
            // Log.Info(Tag, "Intent received: " + intent.Action);
            // read the SendBroadcast data
            if (intent.Action == "com.alr.text")
            {
                string text = intent.GetStringExtra("MyData") ?? "Data not available";
                Toast.MakeText(context, text, ToastLength.Short).Show();
            }
            //read incomming sms
            if (intent.Action == IntentAction)
            {

                SmsMessage[] messages = Telephony.Sms.Intents.GetMessagesFromIntent(intent);

                var sb = new StringBuilder();

                for (var i = 0; i < messages.Length; i++)
                {

                    sb.Append(string.Format("SMS From: {0}{1}Body: {2}{1}", messages[i].OriginatingAddress,
                        System.Environment.NewLine, messages[i].MessageBody));
                }
                Toast.MakeText(context, sb.ToString(), ToastLength.Short).Show();
            }
        }
    }


2- Register class in mainfest or by code

A- From MAinfest
 <uses-permission android:name="android.permission.BROADCAST_SMS" />
  <uses-permission android:name="android.permission.READ_SMS" />
  <uses-permission android:name="android.permission.RECEIVE_SMS" />
  <uses-permission android:name="android.permission.SEND_SMS" />
  <receiver android:name=".SMSReceiver" >
    <intent-filter android:priority="2147483647">
      <action android:name="android.provider.Telephony.SMS_RECEIVED" />
      <action android:name="com.alr.text" />

      <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
  </receiver>
B- By code
   SMSReceiver smsReceiver = new SMSReceiver();
           RegisterReceiver(smsReceiver, new IntentFilter("android.provider.Telephony.SMS_RECEIVED"));

//3-  send  user SendBroadcast
  Intent intent = new Intent();
                intent.SetAction ("com.alr.text");
                intent.PutExtra("MyData", "Data from Activity1");
                SendBroadcast(  intent);

// end  SendBroadcast
UnregisterReceiver(smsReceiver);