android - How to remove data stored on the device remotely through code (programatically) -

i want remove data stored on device remotely through code. did through android device manager. https://www.google.co.in/android/devicemanager want same approach programatically through application.

1) how can active devices through gmail.

2) how can lock mobile

3) how can ring mobile remotely.

i didn't see code programatically. how can programatically these? tried below code.

public class controller extends activity {     public class adminactivity extends deviceadminreceiver {          devicepolicymanager mdpm;         componentname mdeviceadminsample;          protected void oncreate(bundle savedinstancestate) {             super.oncreate(savedinstancestate);              mdpm = (devicepolicymanager)getsystemservice(context.device_policy_service);             mdeviceadminsample = new componentname(controller.this,                 adminactivity.class);         }     }