从 iOS SDK 更新 Mapbox Studio 定义的功能属性？

Question

我在 Mapbox Studio 上创建了自定义地图样式，并上传了具有多个多边形特征的 GeoJSON，该文件如下所示：

{
  "type": "FeatureCollection",
  "name": "AD_micro-regions",
  "crs": {
    "type": "name",
    "properties": {
      "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
    }
  },
  "features": [
    {
      "type": "Feature",
      "id": "AD-01_low_high",
      "properties": {
        "id": "AD-01",
        "elevation": "low_high"
      },
      "geometry": {
        "type": "MultiPolygon",
        "coordinates": [...]
      }
    },
    ... other fetures
  ]

我为创建的图层定义了自定义样式，以便每个要素都根据

danger_level

要素状态（1、2、3、4、5）进行着色：

[
  "match",
  ["feature-state", "danger_level"],
  [1],
  "rgb(134, 231, 75)",
  [2],
  "rgb(249, 219, 73)",
  [3],
  "rgb(235, 134, 52)",
  [4],
  "rgb(216, 69, 49)",
  [5],
  "rgb(184, 64, 46)",
  "rgba(0, 0, 0, 0)"
]

现在我的计划是为 iOS SDK 中的每个功能设置

danger_level

，但我真的找不到方法来做到这一点。

我尝试使用

setFeatureState

但没有效果：

map.setFeatureState(
  sourceId: "composite",
  //sourceLayerId: "micro-regions_elevation-2p16jz",
  featureId: "AD-01_low_high",
  state: ["danger_level": 4],
  callback: { result in
    // This returns `success(<null>)`
    print(result)

    map.getFeatureState(
      sourceId: "composite",
      featureId: "AD-01_low_high",
      callback: { state in
        // This correctly prints `success(["danger_level": 4])`
        // but the map style is not updated
        print(state)
      }
    )                        
  }
)

上面的代码没有效果，状态似乎设置正确，但渲染的地图上没有发生更新。

如果我还指定

sourceLayerId

，第二个

print

语句将返回一个空字典。

如果我打印

map.allSourceIdentifiers

我只会看到这个：

[
  MapboxMaps.SourceInfo(id: "composite", type: MapboxMaps.SourceType(rawValue: "vector")),
  MapboxMaps.SourceInfo(id: "6D9AE", type: MapboxMaps.SourceType(rawValue: "geojson"))
]

我的地图有两个 geojson 图层，而不是一个，6D9AE 会在每次渲染时更改 id。我尝试使用

map.allSourceIdentifiers.last!.id

作为

sourceId

进行

setFeatureState

调用，但没有效果。

我尝试使用

map.layer(withId: "micro-regions_elevation")

检索图层，它正确返回了图层数据：

FillLayer(id: "micro-regions_elevations", type: MapboxMaps.LayerType(rawValue: "fill"), filter: nil, source: Optional("composite"), sourceLayer: Optional("micro-regions_elevation-2p16jz"), slot: nil, minZoom: nil, maxZoom: nil, visibility: MapboxMaps.Value<MapboxMaps.Visibility>.constant(MapboxMaps.Visibility.visible), fillSortKey: nil, fillAntialias: nil, fillColor: Optional(MapboxMaps.Value<MapboxMaps.StyleColor>.expression([match, [get, danger_level], 1, [rgba, 134.0, 231.00001525878906, 75.0, 1.0], 2, [rgba, 249.00001525878906, 219.00001525878906, 73.0, 1.0], 3, [rgba, 235.00001525878906, 134.0, 52.000003814697266, 1.0], 4, [rgba, 216.00001525878906, 69.0, 49.000003814697266, 1.0], 5, [rgba, 184.0, 64.0, 46.0, 1.0], [rgba, 0.0, 0.0, 0.0, 0.0]])), fillColorTransition: nil, fillEmissiveStrength: nil, fillEmissiveStrengthTransition: nil, fillOpacity: Optional(MapboxMaps.Value<Swift.Double>.constant(0.5)), fillOpacityTransition: nil, fillOutlineColor: Optional(MapboxMaps.Value<MapboxMaps.StyleColor>.constant(MapboxMaps.StyleColor(rawValue: "rgba(0.00, 0.00, 0.00, 0.00)"))), fillOutlineColorTransition: nil, fillPattern: nil, fillTranslate: nil, fillTranslateTransition: nil, fillTranslateAnchor: nil)

但我仍然得到相同的结果。

我也尝试了这种替代填充颜色公式，但结果相同：

[
  "case",
  ["==", ["feature-state", "danger_level"], 1],
  "rgb(134, 231, 75)",
  ["==", ["feature-state", "danger_level"], 2],
  "rgb(249, 219, 73)",
  ["==", ["feature-state", "danger_level"], 3],
  "rgb(235, 134, 52)",
  ["==", ["feature-state", "danger_level"], 4],
  "rgb(216, 69, 49)",
  ["==", ["feature-state", "danger_level"], 5],
  "rgb(184, 64, 46)",
  "rgba(0, 0, 0, 0)"
]

我做错了什么？我正在使用 SDK 11.0.0-rc.1

Answer 1

调用以下代码使用过滤器更新图层：

mapView.mapboxMap.style.updateLayer(withId:type:update:)

来自 Mapbox github 的示例

使用表达式并首先在Mapbox Studio上测试它们

func applyMYFilter(for types: [String]) throws {
    try updateMapLayer(withId: "poi-label", ofType: SymbolLayer.self) { layer in
        layer.filter = Expression.match {
            Expression.get(.string("class")),
            types,
            true,
            false
        }
    }
}

func updateMapLayer(withId layerId: String, ofType layerType: SymbolLayer.Type, updateHandler: (inout SymbolLayer) throws -> Void) throws {
    try mapView.mapboxMap.style.updateLayer(withId: layerId, type: layerType) { layer in
        try updateHandler(&layer)
    }
}