@Claude31 Should I add that kind of switch? If yes it is still showing only first VC: switch annotation.title!! {         case "0-One":             annotationView.markerTintColor = UIColor.gray             annotationView.glyphImage = UIImage(named: "one")         case "1-Two":             annotationView.markerTintColor = UIColor.black             annotationView.glyphImage = UIImage(named: "white_flag")             rightButton.addTarget(self, action: #selector(didClickDetailDisclosure2(button:)), for: .touchUpInside)// it should show the second VC but it still shows just this one When I do this:  switch annotation.title {         case 0:            annotationView.markerTintColor = UIColor.gray            annotationView.glyphImage = UIImage(named: "kopula")            rightButton.addTarget(self, action: #selector(didClickDetailDisclosure(button:)), for: .touchUpInside)         case 1:            annotationView.markerTintColor = UIColor.black            annotationView.glyphImage = UIImage(named: "white_flag")            rightButton.addTarget(self, action: #selector(didClickDetailDisclosure2(button:)), for: .touchUpInside)                      } It shows me Expression pattern of type 'Int' cannot match values of type 'String??'

@Claude31 I did sth like this and it changes the icon, but it does not change the VC: switch annotation.title!! {         case "One":             annotationView.markerTintColor = UIColor.gray             annotationView.glyphImage = UIImage(named: "one")         case "Two":             annotationView.markerTintColor = UIColor.black             annotationView.glyphImage = UIImage(named: "two")             rightButton.addTarget(self, action: #selector(didClickDetailDisclosure2(button:)), for: .touchUpInside) What do you mean by setting a tag to each annotation? Is it impossible to do it this way like icon style? Thank you in advance for your help.

Ok, so I've added this and it works with objc function:  @objc func didClickDetailDisclosure(button: UIButton) {         guard let vc = storyboard?.instantiateViewController(withIdentifier: "second_vc") as? SecondController else {                     return                 }                 present(vc, animated: true)     } and this in my mapView func: rightButton.addTarget(self, action: #selector(didClickDetailDisclosure(button:)), for: .touchUpInside) But still I would like each annotation to open each VC. Thank you in advance for your help.