不断的注释渲染是否会减慢我的地图 swiftui

Question

当地图上放置太多注释时，它开始滞后。这似乎是由于缩放导致注释被一遍又一遍地渲染。有没有人有办法让这项工作更有效？ CPU 也跳起来了，但它声称调试可能会弹出数百次警告，我无法修复 whiteout 使区域常量：“不允许从视图更新中发布更改，这将导致未定义的行为。 “

@State var selected : Annotation?
    @State var annotations = [Annotation(coordinates:CLLocationCoordinate2D(latitude: 39.86999190, longitude: -86.04429416), event: false)]
    
    @State private var isPreviewing = false
    
    var body: some View {
        NavigationStack{
            ZStack(alignment: .bottom) {
                Map(coordinateRegion: $locationManager.region , showsUserLocation : true ,annotationItems: annotations )
                {annotation in MapAnnotation(coordinate: annotation.coordinates){
                     //annotations are displayed as buttons
                }
             }
          }
     }

on appear 当地图加载并调用此函数时调用，该函数将注释添加到数组：

func fetchEvents(){
            var newAnnotations1 = self.annotations
            let publicDB = CKContainer.default().publicCloudDatabase
            let date = NSDate(timeInterval: -7.9 * 3600, since: NSDate() as Date)
            let predicate = NSPredicate(format: "creationDate > %@", date)
            let query = CKQuery(recordType: "event", predicate:predicate)
            publicDB.fetch(withQuery: query, inZoneWith: nil)
            { result in
                switch result {
                case .success((let matchResults, _)):
                    for matchResult in matchResults {
                        switch matchResult.1 {
                        case .success(let record):
                            if let location = record["location1"] as? CLLocation
                               {
                                let identified = record.recordID
                                newAnnotations1.append(Annotation(coordinates: location.coordinate,event:true,identify: identified))
                                self.annotations = newAnnotations1
                                }
                        case .failure(let error): print(error)
                        }
                    }
                case .failure(let error): print(error)
                }
            }
        }