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地图框清除管线多段线

mapbox swift ios

sametbilgi · 技术社区 · 7 年前

我可以在地图上绘制多段线路线,但无法从mapview中清除此路线。我的代码是:

func drawRoute() {
    var routeCoordinates = route.coordinates!
    let polyline = MGLPolylineFeature(coordinates: &routeCoordinates, count: route.coordinateCount)
    let source = MGLShapeSource(identifier: "polyline", features: [polyline], options: nil)
    style.addSource(source)
    let layer = MGLLineStyleLayer(identifier: "polyline", source: source)
    layer.lineJoin = MGLStyleValue(rawValue: NSValue(mglLineJoin: .round))
    layer.lineCap = MGLStyleValue(rawValue: NSValue(mglLineCap: .round))
    layer.lineColor = MGLStyleValue(rawValue: UIColor(red: 31 / 255, green: 31 / 255, blue: 31 / 255, alpha: 1))
    layer.lineWidth = MGLStyleValue(interpolationMode: .exponential, cameraStops: [14: MGLStyleValue<NSNumber>(rawValue: 2), 18: MGLStyleValue<NSNumber>(rawValue: 20)], options: [.defaultValue : MGLConstantStyleValue<NSNumber>(rawValue: 1.5)])
    let casingLayer = MGLLineStyleLayer(identifier: "polyline-case", source: source)
    casingLayer.lineJoin = layer.lineJoin
    casingLayer.lineCap = layer.lineCap
    casingLayer.lineGapWidth = layer.lineWidth
    casingLayer.lineColor = MGLStyleValue(rawValue: UIColor(red: 0 / 255, green: 0 / 255, blue: 0 / 255, alpha: 1))
    casingLayer.lineWidth = MGLStyleValue(interpolationMode: .exponential, cameraStops: [14: MGLStyleValue(rawValue: 1), 18: MGLStyleValue(rawValue: 4)], options: [.defaultValue : MGLConstantStyleValue<NSNumber>(rawValue: 1.5)])
    let dashedLayer = MGLLineStyleLayer(identifier: "polyline-dash", source: source)
    dashedLayer.lineJoin = layer.lineJoin
    dashedLayer.lineCap = layer.lineCap
    dashedLayer.lineColor = MGLStyleValue(rawValue: .white)
    dashedLayer.lineOpacity = MGLStyleValue(rawValue: 1.0)
    dashedLayer.lineWidth = layer.lineWidth
    dashedLayer.lineDashPattern = MGLStyleValue(rawValue: [0, 1.5])
    style.addLayer(layer)
    style.addLayer(dashedLayer)
    style.insertLayer(casingLayer, below: layer)
}

我想清除此多段线并用不同的坐标重新绘制。我尝试了removeAnnotation方法,但没用。谢谢

3 回复 | 直到 7 年前

sametbilgi 7 年前

我找到了解决办法。我们可以通过以下标识符访问源 self.mapView.style?.source(withIdentifier: "polyline") 然后将其移除。

Gabo Ruiz 5 年前

我正在处理几乎相同的问题。我需要清理地图并添加另一条多段线。创建多段线的我的代码

 let source = MGLShapeSource(identifier: randomIdentifier, shape: nil, options: nil)

    self.mapView.style?.addSource(source)
    self.polylineSource = source

    let layer = MGLLineStyleLayer(identifier: "polyline", source: source)

错误显示:

“MGLRedundantSourceIdentifierException”,原因:“源多段线” 已存在'。

所以,我发现没有简单的方法可以删除多段线。我创建了一个随机字符串,每次它创建一个新字符串来解决此问题时,都会将其添加到多段线的标识符中

func randomString(length: Int) -> String {
    let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    return String((0..<length).map{ _ in letters.randomElement()! })
}

。。。

func drawRoute(route: Route){

    let randomIdentifier = randomString(length: 8)
    print("random identifier \(randomIdentifier)")

    let source = MGLShapeSource(identifier: randomIdentifier, shape: nil, options: nil)

希望这有帮助

S.S.D Mohamed Dev 6 年前

这对我很有用:

if let source = mapView.style?.source(withIdentifier: "polyline") as? MGLShapeSource {

        source.shape = nil
    }