ios - Custom font for MKAnnotationView Callout -

fortunately, standard callout view mkannotationview meets our needs - title, subtitle, leftcalloutaccessoryview, , rightcalloutaccessoryview.

unfortunately, use custom fonts in our app, , extend custom fonts these callouts.

mkannotationview provides no standard way accomplish this.

how can use custom font in mkannotation's callout view?

since needed swift version - here is. also, have call setneedslayout() on didaddsubview() because otherwise when deselect , reselect annotation layoutsubviews() not called , callout has old font.

// elsewhere, in category on uiview. // answer: http://stackoverflow.com/a/25877372/607876  typealias viewblock = (view : uiview) -> bool  extension uiview {     func loopviewhierarchy(block : viewblock?) {          if block?(view: self) ?? true {             subview in subviews {                 subview.loopviewhierarchy(block)             }         }     } }  // then, in mkannotationview subclass  class customfontannotationview : mkannotationview {      override func didaddsubview(subview: uiview) {         if selected {             setneedslayout()         }     }      override func layoutsubviews() {          // mkannotationviews have subviews if they've been selected.         // short-circuit if there's nothing loop on          if !selected {             return         }          loopviewhierarchy({(view : uiview) -> bool in             if let label = view as? uilabel {                 label.font = labelfont                 return false             }             return true         })     } }