我如何删除Swift 3中的GMSPolyline

问题描述

我正在GoogleMap中制作GMSPolyline。当我想通过编码 polyline.map = nil 来删除GMSPolyline时，但它无法为我工作。

（之前添加了标记，我只需要移除折线）

感谢您的帮助!!!

我的编码：

  func mapView（_ mapView：GMSMapView，didTap标记：GMSMarker） - > Bool {
 // MARK：创建GMSPolyline 
让polyline = GMSPolyline（）
 // MARK：从GoogleMap中移除旧的折线
 polyline.map = nil 
 
 let origin =\（mapView.myLocation！.coordinate.latitude），\（mapView.myLocation！.coordinate.longitude）
 let destination =\（marker.position。纬度），\（marker.position.longitude）
 
 let url =https://maps.googleapis.com/maps/api/directions/json?origin=\（origin） & destination = \（destination）& mode = driving
 
 Alamofire.request（url）.responseJSON {response in 
 
 let json = JSON（data：response .data！）
 let routes = json [routes]。arrayValue 
 
 // MARK：使用Polyline打印路由
用于路由的路由
 {
 let routeOverviewPolyline = route [overview_polyline]。dictionary 
 let points = routeOverviewPolyline？[points]？。stringValue 
让path = GMSPath（fromEncodedPath：points！）
 polyline = GMSPolyline（path：path）
 polyline.strokeWidth = 4 
 polyline.strokeColor = UIColor.yellow 
 polyline.isTappable = true 
 polyline.map = self.mapView 
} 
} 
 return false 
} 
  

解决方案

在地图上添加新的折线之前，您应该先清除地图。 GMSMapView的clear（）函数

  / ** 
 
清除已添加到地图，包括标记，多义线和地面叠加层。 
这不会清除可见的位置点或重置当前的mapType。 
 
 * / 
  

试试这个

  func mapView（_ mapView：GMSMapView，didTap marker：GMSMarker） - > Bool {
 // MARK：创建GMSPolyline 
让polyline = GMSPolyline（）
 // MARK：从GoogleMap中删除旧的多段线
 mapView.clear（）
 // TODO： - 在这里重绘所有标记。 
 let origin =\（mapView.myLocation！.coordinate.latitude），\（mapView.myLocation！.coordinate.longitude）
 let destination =\（marker.position.latitude ），\（marker.position.longitude）
 
 let url =https://maps.googleapis.com/maps/api/directions/json?origin=\(origin )& ; destination = \（destination）& mode = driving
 
 Alamofire.request（url）.responseJSON {response in 
 
 let json = JSON（data：response。数据！）
 let routes = json [routes]。arrayValue 
 
 // MARK：使用Polyline打印路线
用于路线的路线
 {
让routeOverviewPolyline = route [overview_polyline]。字典
 let points = routeOverviewPolyline？[points] ?. stringValue 
 let path = GMSPath（fromEncodedPath：points！）
 polyline = GMSPolyline （路径：路径）
 polyline.strokeWidth = 4 
 polyline.strokeColor = UIColor.yellow 
 polyline.isTappable = true 
 polyline.map = self.mapView 
} 
} 
返回false 
} 
  

I'm making the GMSPolyline in the GoogleMap. When I want to remove the GMSPolyline by coding polyline.map = nil, but it can not working for me. I'm copy some coding in the below.

(added the marker before, I need remove the polyline only)

Thank you for your help!!!

my coding:

func mapView(_ mapView: GMSMapView, didTap marker: GMSMarker) -> Bool {
    //MARK: create the GMSPolyline
    let polyline = GMSPolyline()
    //MARK: remove the old polyline from the GoogleMap
    polyline.map = nil

    let origin = "\(mapView.myLocation!.coordinate.latitude),\(mapView.myLocation!.coordinate.longitude)"
    let destination = "\(marker.position.latitude),\(marker.position.longitude)"

    let url = "https://maps.googleapis.com/maps/api/directions/json?origin=\(origin)&destination=\(destination)&mode=driving"

    Alamofire.request(url).responseJSON { response in

        let json = JSON(data: response.data!)
        let routes = json["routes"].arrayValue

        //MARK: print route using Polyline
        for route in routes
        {
            let routeOverviewPolyline = route["overview_polyline"].dictionary
            let points = routeOverviewPolyline?["points"]?.stringValue
            let path = GMSPath(fromEncodedPath: points!)
            polyline = GMSPolyline(path: path)
            polyline.strokeWidth = 4
            polyline.strokeColor = UIColor.yellow
            polyline.isTappable = true
            polyline.map = self.mapView
        }
    }
    return false
}

解决方案

you should clear the map before adding new polyline on the map.

clear() function of GMSMapView

/**

Clears all markup that has been added to the map, including markers, polylines and ground overlays.
This will not clear the visible location dot or reset the current mapType.

*/

Try this

func mapView(_ mapView: GMSMapView, didTap marker: GMSMarker) -> Bool {
    //MARK: create the GMSPolyline
    let polyline = GMSPolyline()
    //MARK: remove the old polyline from the GoogleMap
    mapView.clear()
    //TODO:- Redraw all marker here.
    let origin = "\(mapView.myLocation!.coordinate.latitude),\(mapView.myLocation!.coordinate.longitude)"
    let destination = "\(marker.position.latitude),\(marker.position.longitude)"

    let url = "https://maps.googleapis.com/maps/api/directions/json?origin=\(origin)&destination=\(destination)&mode=driving"

    Alamofire.request(url).responseJSON { response in

        let json = JSON(data: response.data!)
        let routes = json["routes"].arrayValue

        //MARK: print route using Polyline
        for route in routes
        {
            let routeOverviewPolyline = route["overview_polyline"].dictionary
            let points = routeOverviewPolyline?["points"]?.stringValue
            let path = GMSPath(fromEncodedPath: points!)
            polyline = GMSPolyline(path: path)
            polyline.strokeWidth = 4
            polyline.strokeColor = UIColor.yellow
            polyline.isTappable = true
            polyline.map = self.mapView
        }
    }
    return false
}

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