GeoJSON レイヤー

@StateObject private var layerState = GeoJSONLayerState(
    opacity: 1.0,
    layerStyle: GeoJSONTileRenderer.LayerStyle(
        strokeColor: UIColor(red: 30/255, green: 136/255, blue: 229/255, alpha: 0.86),
        fillColor:   UIColor(red: 30/255, green: 136/255, blue: 229/255, alpha: 0.24),
        strokeWidth: 1.5,
        pointRadius: 8.0
    )
)

// LayerStyle のフィールドは let なので、構造体ごと入れ替えます（alpha は UIColor 側）
layerState.layerStyle = GeoJSONTileRenderer.LayerStyle(
    strokeColor: layerState.layerStyle.strokeColor,
    fillColor:   UIColor.systemRed.withAlphaComponent(0.35),
    strokeWidth: layerState.layerStyle.strokeWidth,
    pointRadius: layerState.layerStyle.pointRadius
)

import { colorArgb, colorRgb, argbToCss } from '@mapconductor/react-geojson-layer';

const layerState = useMemo(() => new GeoJSONLayerState({
  strokeColor: colorArgb(220, 30, 136, 229),
  fillColor:   colorArgb(60, 30, 136, 229),
  strokeWidth: 1.5,
  pointRadius: 8,
  opacity: 1,
  minZoom: 8, maxZoom: 22,
}), []);

// 不透明色なら colorRgb、CSS に落とすなら argbToCss
const legend = argbToCss(colorRgb(30, 136, 229)); // "rgba(30,136,229,1.0000)"

let parsed = GeoJSONParser.parse(data: data)

let styled = parsed.map { f -> GeoJSONFeature in
    switch f.properties["status"] as? String {
    case "alert":
        var copy = f
        copy.fillColor = UIColor.systemRed.withAlphaComponent(0.47)
        copy.strokeWidth = 3.0
        return copy
    case "closed":
        var copy = f
        copy.visible = false
        return copy
    default:
        return f   // nil のままならレイヤー既定値
    }
}

const styled = useMemo(() =>
  GeoJSONParser.parseFeatures(GEOJSON).map(f => {
    const status = f.properties.status;
    if (status === 'alert') {
      return { ...f, fillColor: colorArgb(120, 214, 64, 69), strokeWidth: 3 };
    }
    if (status === 'closed') return { ...f, visible: false };
    return f; // null のままならレイヤー既定値
  }), []);

<GeoJSONLayer state={layerState} features={styled} />