title: Refresh tableView \ View
body: <p>I have tab bar application and when i press on one of the tabs the ViewDidLoad called
  now if i moving to another tab and then return to the previous one the VewDidLoad didnt call
  how can i know that this window load again?</p>
  
  <p>and also how can i refresh a view? for example a viewtable that i made logic changes and want to refresh the new data.</p>
  
  <p>thanks.</p>