title: how to backup contacts or sms to SD card as .xml file or .csv file and restore it later
body: <p>I am trying to develop a feature into my app to backup sms and contacts to SD Card as .xml or .csv format and restore it later.</p>
  
  <p>so please anyone give me some suggestions or some sample code or any resource links related to this.</p>
  
  <p>thanks in advance</p>