title: Listview getting disappeared
body: <p>I am facing one problem with Listview</p>
  
  <p>Description : there are two buttons on the header of the screen, on clicking any of which calls a webservice, gets a response saves that response into an arraylist and I display the data which is there in the arraylist in the listview. First time whenever a button is clicked data is displayed into the listview but whenever the button is clicked second time previous listview get disappeared on pre-execute of Asynctask and is populated again when the webservice call is done, but my problem is I dont want my listview to get disappeared until the web service call is finished.</p>