Swift - 从地图中的当前位置选择注释的方向

Question

我的应用程序目前有一个本地搜索,可以为搜索结果添加注释.我想设置它,当您选择注释并单击调出按钮时,它将在地图应用程序中打开,其中包含指向当前设备位置注释的说明.我遇到了一些问题.

首先,我的注释按钮没有出现.其次,我认为我没有正确检测选定的注释.

这是我的搜索和选择注释的代码:

func performSearch() {

    matchingItems.removeAll()
    let request = MKLocalSearchRequest()
    request.naturalLanguageQuery = searchText.text
    request.region = mapView.region

    let search = MKLocalSearch(request: request)

    search.startWithCompletionHandler({(response:
        MKLocalSearchResponse!,
        error: NSError!) in

        if error != nil {
            println("Error occured in search: \(error.localizedDescription)")
        } else if response.mapItems.count == 0 {
            println("No matches found")
        } else {
            println("Matches found")

            for item in response.mapItems as! [MKMapItem] {
                println("Name = \(item.name)")
                println("Phone = \(item.phoneNumber)")

                self.matchingItems.append(item as MKMapItem)
                println("Matching items = \(self.matchingItems.count)")

                var annotation = MKPointAnnotation()
                var coordinates = annotation.coordinate
                annotation.coordinate = item.placemark.coordinate
                annotation.title = item.name
                self.mapView.addAnnotation(annotation)

            }
        }
    })
}



func mapView(mapView: MKMapView!, annotationView view: MKAnnotationView!,
    calloutAccessoryControlTapped control: UIControl!) {

        if self.mapView.selectedAnnotations?.count > 0 {

            if let selectedLoc = self.mapView.selectedAnnotations[0] as? MKAnnotation {
                println("Annotation has been selected")
                let currentLoc = MKMapItem.mapItemForCurrentLocation()
                let mapItems = NSArray(objects: selectedLoc, currentLoc)
                let launchOptions = [MKLaunchOptionsDirectionsModeKey: MKLaunchOptionsDirectionsModeDriving]
                MKMapItem.openMapsWithItems([selectedLoc, currentLoc], launchOptions: launchOptions)
            }
        }

}

任何帮助将不胜感激,提前感谢.

Answer 1

第一期:

需要在viewForAnnotation委托方法中明确设置标注按钮(默认红色引脚没有).这是一个可能实现的简单示例:

func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {

    if annotation is MKUserLocation {
        return nil
    }

    let reuseId = "pin"

    var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
    if pinView == nil {
        pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        pinView!.canShowCallout = true
        pinView!.pinColor = .Purple

        //next line sets a button for the right side of the callout...
        pinView!.rightCalloutAccessoryView = UIButton.buttonWithType(.DetailDisclosure) as! UIButton
    }
    else {
        pinView!.annotation = annotation
    }

    return pinView
}

对于第二个问题:

首先,在中calloutAccessoryControlTapped,可以直接访问注释,view.annotation因此使用selectedAnnotations数组是不必要的.

接下来,openMapsWithItems预计数组MKMapItem对象,但在数组中您传递([selectedLoc, currentLoc]),selectedLoc是不是一个MKMapItem-它只是一些对象实现MKAnnotation.

运行此代码将导致此错误崩溃:

- [MKPointAnnotation dictionaryRepresentation]:发送到实例的无法识别的选择器

当地图应用尝试使用时selectedLoc,就像它是一个MKMapItem.

相反,您需要MKMapItem从selectedLoc注释创建一个.这可以通过首先MKPlacemark使用注释MKPlacemark(coordinate:addressDictionary:)创建注释然后使用创建MKMapItem地标来完成MKMapItem(placemark:).

例:

func mapView(mapView: MKMapView!, annotationView view: MKAnnotationView!,
    calloutAccessoryControlTapped control: UIControl!) {

        let selectedLoc = view.annotation

        println("Annotation '\(selectedLoc.title!)' has been selected")

        let currentLocMapItem = MKMapItem.mapItemForCurrentLocation()

        let selectedPlacemark = MKPlacemark(coordinate: selectedLoc.coordinate, addressDictionary: nil)
        let selectedMapItem = MKMapItem(placemark: selectedPlacemark)

        let mapItems = [selectedMapItem, currentLocMapItem]

        let launchOptions = [MKLaunchOptionsDirectionsModeKey: MKLaunchOptionsDirectionsModeDriving]

        MKMapItem.openMapsWithItems(mapItems, launchOptions:launchOptions)
}