Swift - 将不同的图像从数组设置到注释引脚

Question

我想知道如何将不同的图像设置为 mapview 上的注释图钉。以下问题的区别

viewForAnnotation confusion and customizing the pinColor iteratively

Swift different images for Annotation

我的图像数组是根据服务器响应动态生成的。数组没有固定大小，因此 switch/case 构造不是一个好主意。此外，我不确定如何应用上述主题中提到的自定义类的解决方案。我知道最好对之前提出的问题之一发表评论，但不幸的是，我现在太菜鸟了，不能这样做（分数太少）。

这是在显示地图的函数内部执行的 for 循环：

for var r=0;r<arrayOfRestaurants.count;r++
    {

        var summonRestaurant:NSDictionary = arrayOfRestaurants[r] as NSDictionary
        var nearbyRestaurant = Restaurant(nearbyRestaurants:summonRestaurant)
        var latRestaurant=(nearbyRestaurant.latitude as NSString).doubleValue
        var longRestaurant=(nearbyRestaurant.longitude as NSString).doubleValue
        var locationOfRestaurant = CLLocationCoordinate2D(
            latitude: latRestaurant as CLLocationDegrees, longitude: longRestaurant as CLLocationDegrees)
        var lunchArray: NSArray = nearbyRestaurant.lunch as NSArray
        var annotation = MKPointAnnotation()

        annotation.setCoordinate(locationOfRestaurant)
        annotation.title = nearbyRestaurant.name + "  " + nearbyRestaurant.distance + " km"
        map.addAnnotation(annotation)
}

这里是 viewForAnnotation 委托方法（与上述线程中使用的方法完全相同）：

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

        if annotation is MKUserLocation {
            //return nil so map view draws "blue dot" for standard user location
            return nil
        }

        let reuseId = "pin"

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

            pinView!.image = globalImageArray[0]

            }
        else {
            pinView!.annotation = annotation
        }

        return pinView
}

如您所见，我为 pinView 分配了一个特定图像，即 globalImageArray[0]，但我正在寻找一种解决方案，让我遍历 globalImageArray 并为每个 pin 分配特定图像。

很高兴得到任何帮助，在此先感谢！

Answer 1

首先，您需要创建自己的类，该类采用MKAnnotation 协议进行注释 -

class RestaurantAnnotation : NSObject, MKAnnotation {
    var coordinate: CLLocationCoordinate2D
    var title: String
    var subtitle: String
    var image: UIImage?

    init(coordinate: CLLocationCoordinate2D, title: String, subtitle: String) {
        self.coordinate = coordinate
        self.title = title
        self.subtitle = subtitle
    }
}

然后，在添加注解和设置图片的时候使用这个类的实例——

for var r=0;r<arrayOfRestaurants.count;r++
    {

        var summonRestaurant:NSDictionary = arrayOfRestaurants[r] as NSDictionary
        var nearbyRestaurant = Restaurant(nearbyRestaurants:summonRestaurant)
        var latRestaurant=(nearbyRestaurant.latitude as NSString).doubleValue
        var longRestaurant=(nearbyRestaurant.longitude as NSString).doubleValue
        let locationOfRestaurant = CLLocationCoordinate2D(
            latitude: latRestaurant as CLLocationDegrees, longitude: longRestaurant as CLLocationDegrees)
        var lunchArray: NSArray = nearbyRestaurant.lunch as NSArray

        let title = nearbyRestaurant.name + "  " + nearbyRestaurant.distance +" km"
        var annotation = RestaurantAnnotation(coordinate, title:title, subtitle:"")
        annotation.image = globalImageArray[r]
        map.addAnnotation(annotation)
}

现在，在您的注释视图中，您可以访问图像 -

func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
    if !(annotation is RestaurantAnnotation) {
        return nil
    }

    let reuseId = "restaurant"
    var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
    if anView == nil {
        anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        anView.canShowCallout = true
    }
    else {
        anView.annotation = annotation
    }

    let restaurantAnnotation = annotation as RestaurantAnnotation

    if (restaurantAnnotation.image != nil) {
            anView.image = restaurantAnnotation.image!
            anView.image.layer.setCornerRadius(8.0)
            anView.image.layer.clipsToBounds=true
        }
        else {
         // Perhaps set some default image
        }

    return anView
}