Pietro Messineo Pietro Messineo - 22 days ago 14
Swift Question

Use of unresolved identifier 'showAlert' Swift

Hello guys I'm new in Swift and I'm stacked with this piece of code and every time it return to me "Use of unresolved identifier 'showAlert' for User enter region and User exit region:

func setupData() {
// 1. check if system can monitor regions
if CLLocationManager.isMonitoringAvailable(for: CLCircularRegion.self) {

// 2. region data
let title = "Primo punto"
let coordinate = CLLocationCoordinate2DMake(38.121973, 13.360855)
let regionRadius = 300.0

// 3. setup region
let region = CLCircularRegion(center: CLLocationCoordinate2D(latitude: coordinate.latitude,
longitude: coordinate.longitude), radius: regionRadius, identifier: title)
locationManager.startMonitoring(for: region)

// 4. setup annotation
let restaurantAnnotation = MKPointAnnotation()
restaurantAnnotation.coordinate = coordinate;
restaurantAnnotation.title = "\(title)";
mapView.addAnnotation(restaurantAnnotation)

// 5. setup circle
let circle = MKCircle(center: coordinate, radius: regionRadius)
mapView.add(circle)
}
else {
print("System can't track regions")
}
}

// 6. draw circle
func mapView(mapView: MKMapView, rendererForOverlay overlay: MKOverlay) -> MKOverlayRenderer {
let circleRenderer = MKCircleRenderer(overlay: overlay)
circleRenderer.strokeColor = UIColor.red
circleRenderer.lineWidth = 1.0
return circleRenderer
}

// 1. user enter region
func locationManager(manager: CLLocationManager, didEnterRegion region: CLRegion) {
showAlert("enter \(region.identifier)")
}

// 2. user exit region
@nonobjc func locationManager(manager: CLLocationManager, didExitRegion region: CLRegion) {
showAlert("exit \(region.identifier)")
}


}

Thanks guys!

Answer

I don't know if you have a 'showAlert()' function but if you are trying to alert the user then you can do it like this:

//Create alert
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)

// Add action buttons to the alert
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))

// Present the alert to the view
self.present(alert, animated: true, completion: nil)

if you want to make it as a function then just create one called show alerts and add your own parameters to the function. Like this:

func showAlert(Title: String, Message: String) {
    let alert = UIAlertController(title: Title, message: Message, preferredStyle: UIAlertControllerStyle.alert)
    alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))
    self.present(alert, animated: true, completion: nil)
}
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