在 Swift 中访问 function 之外的变量

Question

I want to call a variable (var view) that it is defined in another function (func mapView).

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView?{
   if annotation is MapSeismometerAnnotation{
     if let annotation = annotation as? MapSeismometerAnnotation{
        var view: MKPinAnnotationView
        view = MKPinAnnotationView(annotation: annotation,reuseIdentifier:annotation.identifier)
        ...
        ...
}
@IBAction func pressPlay(_ sender: Any){
    //I want to call here the variable view
}

My class is:

class MapViewController: UIViewController,MKMapViewDelegate,CLLocationManagerDelegate,SCSEarthquakesHandler,SCSPublicSeismometersHandler{

If I define the variable var view: MKPinAnnotationView under the class (outside the function), Xcode return me this error:

Cannot override mutable property 'view' of type 'UIView?' with covariant type 'MKPinAnnotationView'

How can I solve this?

Answer 1

Set another name

var otherName: MKPinAnnotationView

view variable name conflicts with the vc's UIView property

Answer 2

View is not overridable because it is used by the UIViewController . Therefore you need to assign another name to the variable than view .

For example: var annotationView: MKAnnotationView is allowed.

Answer 3

view is already defined variable in UIViewController. Pick another name for your MKPinAnnotationView