i want to send SMS from Android application using SMS manager

Question

I have tried sending but the SMS is automatically sent without getting known. I want to send SMS with field of To to be predefined from my code and can get

Answer 1

You can use here this method to send your message in predefine phone number.

 void sendSMS(String phoneNumber, String message)
    {      
        String SENT = "SMS_SENT";
        String DELIVERED = "SMS_DELIVERED";

        PendingIntent sentPI = PendingIntent.getBroadcast(this, 0,
            new Intent(SENT), 0);

        PendingIntent deliveredPI = PendingIntent.getBroadcast(this, 0,
            new Intent(DELIVERED), 0);

        //---when the SMS has been sent---
        registerReceiver(new BroadcastReceiver(){
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode())
                {
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS sent", 
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                        Toast.makeText(getBaseContext(), "Generic failure", 
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_NO_SERVICE:
                        Toast.makeText(getBaseContext(), "No service", 
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_NULL_PDU:
                        Toast.makeText(getBaseContext(), "Null PDU", 
                                Toast.LENGTH_SHORT).show();
                        break;
                    case SmsManager.RESULT_ERROR_RADIO_OFF:
                        Toast.makeText(getBaseContext(), "Radio off", 
                                Toast.LENGTH_SHORT).show();
                        break;
                }
            }
        }, new IntentFilter(SENT));

        //---when the SMS has been delivered---
        registerReceiver(new BroadcastReceiver(){
            @Override
            public void onReceive(Context arg0, Intent arg1) {
                switch (getResultCode())
                {
                    case Activity.RESULT_OK:
                        Toast.makeText(getBaseContext(), "SMS delivered", 
                                Toast.LENGTH_SHORT).show();
                        break;
                    case Activity.RESULT_CANCELED:
                        Toast.makeText(getBaseContext(), "SMS not delivered", 
                                Toast.LENGTH_SHORT).show();
                        break;                        
                }
            }
        }, new IntentFilter(DELIVERED));        

        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI);        
    }

Answer 2

private void sendSMS(String phoneNumber, String message)
    {
        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phoneNumber, null, message, null, null);
    }

Call this method like 

btnSendSMS.setOnClickListener(new View.OnClickListener()
        {

            public void onClick(View v)
            {
                sendSMS("5556", "Hello my friends!");

            }
        });

Add these into your manifest: