ios - Mapbox 清除路线折线

Question

我可以在 map 上绘制折线路线，但我无法从 map View 中清除这条路线。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)
}

我想清除这条折线并用不同的坐标重新绘制。我尝试了 removeAnnotation 方法，但没有帮助。谢谢。

Answer 1

我找到了解决方案。我们可以使用 self.mapView.style?.source(withIdentifier: "polyline") 这样的标识符访问源，然后将其删除。