Android: onCreate being invoked repeatedly
<p>I have an activity in which i need to implement a basic mm::ss timer . Below is the code i have written for it. However the problem is that when i press the back button in the emulator and click on the app again, the values change much faster. It looks like the onCreate is being called again. How do i rectify this?
I have tried creating a boolean variable and setting it to true the first time the task is invoked . I call the startPeriodidUpdates() only when the value is false.But the onCreate creates the variable again with the value of false.</p>

<pre><code>   public class GraphicsActivity extends Activity {
static int seconds = 0;
static int minutes = 0;
public static String time_elapsed;
public static boolean clearView = true;
Handler myhandler = new Handler();
public static String min,sec;  
public static boolean running = true;


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

    } 
    public void onResume(){
    super.onResume();
    } 
    public void onPause() {
    super.onPause();    
    }
   public void onStop(){
   super.onStop();
    }

   public void startPeriodicUpdates()
   {
periodicCall();
   }
   public void stopPeriodicUpdates(){ 
     myhandler.removeCallbacksAndMessages(myhandler);
   }

   public  void periodicCall()
    {

seconds++;
if(seconds ==60)
{
    seconds=0;
    minutes++;
    if(minutes==60)
    {
        seconds=0;
        minutes=0;
    }
}
// left-padding zeros to the minutes and seconds values
min = String.format("%02d",minutes);
sec = String.format("%02d",seconds);
time_elapsed =  min + ":" + sec;
time_elapsed =  min + ":" + sec + "";
myhandler.postDelayed(new Runnable(){
    public void run(){
        periodicCall();

    }
},1000);
</code></pre>

<p>}</p>
