Question

i am developing APP which send sms to Number, if SMS failed the Asynctask execute and check after interval to resend sms again but, all my work wasted because i don’t understand the Asynctask here is my Code.

ASYNC Class

        class checkList extends AsyncTask<String, Void, Void> {
        public Void doInBackground(String... p) {
          while (true) {
                already_running_async=true;
              sms.sendTextMessage(phone_nr, null, "SmS Sending", sentPI, null);

              try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
              if (isCancelled()) break;

          }
        return null;
        }
        };

SMS sending Code and Error Handling

        bol=false;
    already_running_async=false;
    check=false;

sms = SmsManager.getDefault();
        if(!phone_nr.equals(""))
            sms.sendTextMessage(phone_nr, null,"Sms body" , sentPI, null); 
        sendBroadcastReceiver = new BroadcastReceiver(){
         @Override
            public void onReceive(Context context, Intent intent) {
                switch (getResultCode())
                {
                   case Activity.RESULT_OK:
                       //sms sent if bol true cancel the Asynctask :)
                    if(bol){
                    new checkList().cancel(true);}
                    break;
                    case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                        if(already_running_async==false){
                        new checkList().execute();
                        bol=true;}
                        break;
                    case SmsManager.RESULT_ERROR_NO_SERVICE:
                        if(already_running_async==false){
                        new checkList().execute();
                        bol=true;}
                        break;
                    case SmsManager.RESULT_ERROR_NULL_PDU:
                        if(already_running_async==false){
                        new checkList().execute();
                        bol=true;}
                        break;
                    case SmsManager.RESULT_ERROR_RADIO_OFF:
                        if(already_running_async==false){
                        new checkList().execute();
                        bol=true;}
                        break;
                }

           }
        };
        registerReceiver(sendBroadcastReceiver , new IntentFilter(SENT));

Problem:
task starts but task remain alive and send sms repeatedly after 10 second i have also put the cancel but asyntask doesnot cancel after successfull sms is sent

Please Help i havent Slept for Night because of this problem 🙁

Regards

Answer 1

This case creates a new asynctask that is immediately canceled.

case Activity.RESULT_OK:
    //sms sent if bol true cancel the Asynctask :)
    if(bol){
        new checkList().cancel(true);
    }
    break;

To cancel the AsyncTask you need to store it in a variable, like

checkList smsTask = new checkList();
smsTask.execute();

// Other app logic

// Replacing the internal portion of that case is the new cancel code
if (bol) {
    smsTask.cancel(true);
}