如何在swift / iOS中更新Google Maps标记位置

I would like to have multiple markers and update their position, based on new data from server. This is how I show marker on map (basic stuff):

我希望有多个标记,并根据服务器的新数据更新它们的位置。这就是我在地图上显示标记的方法(基本内容):

func showMarkerOnMap() {
    mapView.clear() //<- That's GMSMapView
    for all in dataFromServer {
        let lat5 = all.latitude
        let lon5 = all.longitude
        let position = CLLocationCoordinate2DMake(lat5, lon5)
        let marker = GMSMarker(position: position)
        marker.flat = true
        marker.map = self.mapView
    }
}

This is how I get dataFromServer using Alamofire:

这就是我使用Alamofire获取dataFromServer的方法:

var dataFromServer = [dataClass]()
func getCoordinatesFromServer(){

    //Here goes headers and authentication data

    Alamofire.request(.GET, URL, headers: headers).authenticate(user: oranges, password: appels).responseJSON { response in
        switch response.result {
        case .Success:
            //Remove existing dataFromServer
            self.dataFromServer.removeAll()

            if let value = response.result.value {
                let json = JSON(value)

                for result in json.arrayValue {
                    let lat = result["latitude"].doubleValue
                    let lon = result["longitude"].doubleValue

                    let zip = dataClass(latitude: lat, longitude: lon)
                    //The next part is for checking that coordinates do not overlap
                    if self.dataFromServer.count < 1 {
                        self.dataFromServer.append(zip)     
                    } else {
                        for all in self.dataFromServer {
                            guard all.latitude != lat else {
                                    return
                                }
                                self.trblInfo1.append(zip)
                            }
                    }
                }
                //This should update existing markers?
                self.showMarkerOnMap()
            }
        case .Failure(let error):
            print(error)
        }
    }
}

Basically I just append all received data to my dataFromServer which belongs to dataClass class:

基本上我只是将所有收到的数据附加到属于dataClass类的dataFromServer:

class dataClass: NSObject {
var latitude: Double
var longitude: Double

init(latitude: Double, longitude: Double) {
    self.latitude = latitude
    self.longitude = longitude       
  }
}

My getCoordinatesFromServer() function is being called every 3 seconds (for now). What I was expecting to receive new coordinates (and I do receive them for sure), thenshowMarkerOnMap() should be called thus clearing all existing markers and creating news. What I get - marker duplicate and noticeable lag. The original marker disappears if go to another View and then comeback to View containing mapView.

我的getCoordinatesFromServer()函数每3秒调用一次(现在)。我期待接收新坐标(我确实收到它们),应该调用thenshowMarkerOnMap(),从而清除所有现有标记并创建新闻。我得到了什么 - 标记重复和显着滞后。如果转到另一个视图然后返回到包含mapView的View,原始标记将消失。

Any suggestion on how to improve my code or some alternative?

关于如何改进我的代码或其他替代方案的任何建议?

1 个解决方案

#1

If you have any kind of unique identifier for your positions that came from server, you can keep a list of markers and then update their location when new data arrive. Something like this:

如果您有来自服务器的职位的任何类型的唯一标识符,您可以保留标记列表,然后在新数据到达时更新其位置。像这样的东西:

for result in json.arrayValue {

     let lat = result["latitude"].doubleValue
     let lon = result["longitude"].doubleValue

     let identifier = result["identifier"] as! String
     self.myMarkersDictionary[identifier]?.position.latitude = lat
     self.myMarkersDictionary[identifier]?.position.longitude = lon
     ...    
}