MapKit:如何在移动其中一个注记时更新地图上的折线

Question

我正在开发一个像Uber这样的应用程序。我成功地在地图上绘制了用户和驾驶员之间的线，但我还希望跟踪驾驶员的移动，如何根据驾驶员的移动更新折线。

注意:我有一个API，可以获取驱动程序的当前位置。

let sourcePlaceMark = MKPlacemark(coordinate: sourceLocation, addressDictionary: nil)
    let destinationPlaceMark = MKPlacemark(coordinate: destinationLocation, addressDictionary: nil)
    let sourceMapItem = MKMapItem(placemark: sourcePlaceMark)
    let destinationItem = MKMapItem(placemark: destinationPlaceMark)
    let sourceAnotation = MKPointAnnotation()
    sourceAnotation.title = sourceAddress
    if let location = sourcePlaceMark.location {
        sourceAnotation.coordinate = location.coordinate
    }
    let destinationAnotation = MKPointAnnotation()
    destinationAnotation.title = destinationAddress
    if let location = destinationPlaceMark.location {
        destinationAnotation.coordinate = location.coordinate
    }
    mapView.showAnnotations([sourceAnotation, destinationAnotation], animated: true)
    
    let directionRequest = MKDirections.Request()
    directionRequest.source = sourceMapItem
    directionRequest.destination = destinationItem
    directionRequest.transportType = .automobile
    let direction = MKDirections(request: directionRequest)
    direction.calculate { (response, error) in
        guard let response = response else {
            if let error = error {
                print("ERROR FOUND : \(error.localizedDescription)")
            }
            return
        }
        let route = response.routes[0]
        mapView.addOverlay(route.polyline, level: MKOverlayLevel.aboveRoads)

Answer 1

你已经有了最重要的部分，获取司机的位置，并绘制一条通往它的路线。

现在，您只需运行一个timer并定期执行以下步骤：

• get driver location
• 检查新位置是否与先前的location
• calculate不同(超出某个阈值)具有更新的location
• remove旧路径折线叠加
• 添加新路径折线叠加