Sending SMS messages

Hi all,
in Android there are two ways to send SMS messages.
The first is to delegate the send action to SMS application by intent:
 

Intent sendIntent = new Intent(Intent.ACTION_VIEW);
sendIntent.putExtra("sms_body", "Content of the SMS goes here..."); 
sendIntent.setType("vnd.android-dir/mms-sms");
startActivity(sendIntent);

The second way is to use the SmsManager (added in API level 4):

//---sends an SMS message to another device---
    private void sendSMS(String phoneNumber, String message)
    {        
        PendingIntent pi = PendingIntent.getActivity(this, 0,
            new Intent(this, SMS.class), 0);                
        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phoneNumber, null, message, pi, null);        
    }

To use the second method you need to add the permission to the manifest, because you send the message directly

Intercept SMS with Broadcast Receiver

Hi developers,

in Android Broadcast Receivers are used to listen for broadcast Intents. A Broadcast Receiver needs to be registered, either in code or within the application manifest. (in this case is registered in the manifest)
When registering a Broadcast Receiver you must use an Intent Filter to specify which Intents it is listening for.

We use BroadcastReceiver to intercept SMS.
See the code below

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.widget.Toast;

public class SMSBroadcastReceiver extends BroadcastReceiver{
        @Override
 public void onReceive(Context context, Intent intent) {
  Bundle bundle = intent.getExtras();
  SmsMessage[] msgs = null;
  StringBuilder str = new StringBuilder();
  if (bundle != null) {
   // --- retrieve the received SMS here ---
   Object[] pdus = (Object[]) bundle.get("pdus");
   msgs = new SmsMessage[pdus.length];
   for (int i = 0; i < msgs.length; i++) {
    msgs[i] = SmsMessage.createFromPdu((byte[]) pdus[i]);
    str.append("SMS from " + msgs[i].getOriginatingAddress());
    str.append(" :");
    str.append(msgs[i].getMessageBody().toString());
    str.append("\n");
   }
   // ...we show sms here...
   Toast.makeText(context, str.toString(), Toast.LENGTH_SHORT).show();
  }
 }
}

As you can see, we extends from BroadcastReceiver and override the method onReceive where we retrieve information about the received SMS.

In the manifest you must define the RECEIVE_SMS uses-permission, register the receiver (our class SMSBroadcastListener) and his intent-filter (SMS_RECEIVED):

They will be started automatically when a matching Intent is broadcast, in practice when received an SMS you will see a Toast with SMS information.