ios - Detecting when tabBar item is pressed when is page -

i have uitabbar 4 tabs.

i want specific function called in each viewcontroller of tab when tabbaritem pressed twice (like, user on profilevc , presses on profile item, want refresh view).

how can detect when user pressed on tab in view now?

thank you!

one option refreshing inside viewwillappear() method. , second 1 considerably long.

in parent view controller

protocol parentdelegate {      func refresh() }  class landingviewcontroller: uiviewcontroller, uitabbardelegate {      var delegate: parentdelegate?     var selecteditem: uitabbaritem!      override func viewdidload() {         super.viewdidload()         self.tabbar.delegate = self         self.selecteditem = self.tabbar.selecteditem     }      override func prepareforsegue(segue: uistoryboardsegue, sender: anyobject?) {          if segue.identifier == "seguenamefordestinationviewcontroller1" {              if let vc = segue.destinationviewcontroller as? yourdestinationviewcontroller1 {                 self.delegate = vc.self             }          } else if segue.identifier == "seguenamefordestinationviewcontroller2" {              if let vc = segue.destinationviewcontroller as? yourdestinationviewcontroller2 {                 self.delegate = vc.self             }          }     }      func tabbar(tabbar: uitabbar, didselectitem item: uitabbaritem) {          if self.selecteditem == item {             self.delegate?.refresh()         }         self.selecteditem = item     } } 

in each tab view controller,

class tabviewcontroller: uiviewcontroller, parentdelegate {      func refresh() {         //write code here     } }