Question

I am doing one application using proximity sensor in android. when any object(finger) comes near to proximity sensor it is working fine. But I want to work application when the object should come second time near to proximity within one second of time. For example my application will lock a phone when finger comes near to proximity on first time. I want lock a phone when same object come near to proximity within second of time. my code is like below:

@Override
 public void onSensorChanged(SensorEvent event) {
  // TODO Auto-generated method stub
  if(count >=0){
    System.out.println("inside on sensor changed*****");
        ProximityReading.setText("Proximity Sensor Reading:"
                + String.valueOf(event.values[0])); 
       count++;
      System.out.println("inside count*****"+count);
  }
  if(count == 1){
    System.out.println("inside second if *****");
    System.out.println("inside second if*****"+count);
     count = 0; 
    mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);                   
     mDeviceAdminSample = new ComponentName(Controller.this,
                                LockScreenActivity.class);              
    active = mDPM.isAdminActive(mDeviceAdminSample);
    System.out.println("valuve of active"+active);

   if(active){
       System.out.println("***inside if");
           mDPM.lockNow();
       System.out.println("***inside active after if");

     }  

   }

But it is not working :(. plz help me and how to set a timer between first and second time object comes to near. thax in advance

Answer 1

When you capture the first proximity event, save the timestamp using System.currentTimeInMillis(). Do the same for the second proximity event and compare the timestamps.

if(secondTime-firstTime < 1000)
  //doTask