Question

Oh man, I have googled my pants off and had no luck with errors for a couple of days now.

In short, I want to receive an sms that has a message device : command so e.g. SPA:ON

My app is super simple, all I want to do is change a text that displays the status of a device in the MainActivity ( so i.e. change the @string/somevalue in the XML) so that when I receive a SPA:ON message my TextView changes from the initial string of OFF to the new command text of ON.

Whats the best way to do this given my code below??

If it’s not possible – what do I do?

Thanks

public class MainActivity extends Activity {

    private static Button buttonSend;
    private static EditText textPhoneNo;
    private static EditText textSMS;
    private static Context context;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        buttonSend = (Button) findViewById(R.id.buttonSend);
        textPhoneNo = (EditText) findViewById(R.id.editTextPhoneNo);
        textSMS = (EditText) findViewById(R.id.editTextSMS);

        buttonSend.setOnClickListener(new OnClickListener() {

            @Override
        public void onClick(View v) {   

            String phoneNo = textPhoneNo.getText().toString();
            String sms = textSMS.getText().toString();  

            if (phoneNo.length()>0 && sms.length()>0) 
            {
                sendSMS(phoneNo, sms);
            }
            else
            {
                Toast.makeText(getBaseContext(), 
                    "Please enter both phone number and message.", 
                    Toast.LENGTH_SHORT).show();
            }
        }
        });
    }  

    //---sends a SMS message to another device---
    public void sendSMS(String phoneNo, 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 context, Intent intent) {
                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 context, Intent intent) {
                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));         

        try 
        {
            SmsManager sms = SmsManager.getDefault();
            sms.sendTextMessage(phoneNo, null, message, sentPI, deliveredPI);
        } 
    catch (Exception e) 
        {
            Toast.makeText(getApplicationContext(),
                "SMS faild, please try again.",
                Toast.LENGTH_LONG).show();
            e.printStackTrace();
        }
    }       
}

And the SMS code to receive (and attempt to do the text update) is:

public class SmsReceiver extends BroadcastReceiver
{
    @Override
    public void onReceive(Context context, Intent intent) 
    {
        //---get the SMS message passed in---
    Bundle bundle = intent.getExtras();        
    SmsMessage[] msgs = null;
    String str = "";    

    if (bundle != null)
    {
        //---retrieve the SMS message received---
        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 += "SMS from :" + msgs[i].getOriginatingAddress();                     
            str += " :";
            str += msgs[i].getMessageBody().toString();
            str += "\n";        
        }
        //---display the new SMS message---
        Toast.makeText(context, str, Toast.LENGTH_LONG).show(); 

        //---update the device status from the command---
        /* SOME HOW I WANT TO DO:

        String toast_msg = "None";
        String temp[];
        temp = str.split("\\:");
        String device = temp[0];
        String cmd = temp[1];

        TextView t = (TextView) findViewById(R.id.textViewSPAStatus);

        t.setText(cmd);

        Toast.makeText(getBaseContext(), 
                toast_msg, 
                Toast.LENGTH_SHORT).show(); 
        */
    }                       
}
}

Answer 1

You cannot modify the xml, those values are permanent to the xml. What you can use instead:

• SharedPreferences
• SQLite Databases
• A file

SharedPreferences is the simplest to set up and works quite well, and although the text Preferences is part of the name, it is not limited to settings, since it’s a simple key-value pair storage option. So after setting it up, your app will use this as the centralized “command text” database. This means when your Activity is created/resumed you update the TextView with whatever the SharedPreferences has. Nice thing about SharedPreferences is that you can make a separate simple database just for your commands and unless the user deletes your app data, it is one of the safest storage options for values that your app needs persisting across reboots, exits, etc.

Also, to ensure that your receiver can receive all the messages, you might want to consider making a background Service that registers your Recevier.