DialogStateListenerDemo.java

       ... 
       mDialog.setOnShowListener(this);
       mDialog.setOnCancelListener(this);
       mDialog.setOnDismissListener(this);
    }
    
    @Override
    public void onShow(DialogInterface dialogInterface) {
        // Dialog is Displayed
    }

    @Override
    public void onCancel(DialogInterface dialogInterface) {
        // Dialog is Cancelled
    }

    @Override
    public void onDismiss(DialogInterface dialogInterface) {
        // Dialog is Dismissed
    }
}