如何在Leaflet中创建具有绘制多边形功能的按钮？

Question

我想创建一个按钮，其功能与传单中的工具栏相同 map.When 按下后，用户可以在地图上绘制图形 onCreate 函数，但我不知道如何使用此按钮绘制多边形的选项。

这是我初始化传单地图的组件代码：

export class Dashboard extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      filenames: [],
      downloadURLs: [],
      lat: 42.696295,
      lng: 23.303643,
      zoom: 10,
      image: null,
      url: "",
      progress: 0,
      files: [],
      uploadValue: 0,
      filesMetadata: [],
      rows: [],
    };
  }
  //Set location when the map is visualized

  mapRef = createRef();



  onCreate = (e) => {
    var layer = e.layer;
    console.log("Polygon Cordinates", layer.getLatLngs());
    console.log("Log_Create_Shape: ", e);

    var drawedCord = layer.toGeoJSON().geometry.coordinates;
    for (const result of drawedCord) this.props.saveData(result);

    console.log("shape1", drawedCord);

    var data = layer.toGeoJSON();
    var convertedData = "text/json;charset=utf-8," + JSON.stringify(data);
    console.log(convertedData);
    var FileSaver = require("file-saver");
    var blob = new Blob([convertedData], { type: "text/plain;charset=utf-8" });
    FileSaver.saveAs(blob, "cordinates.json");
  };



  componentDidMount() {}

  render() {

      return (

这是我的地图：

    <div id="map" className="dashboard container">
              <br />
              <HorizontalLinearStepper />
              <br />
              <hr />
<button>Draw polygon</button>
              <br />
              <Map
            style={{ height: "50vh" }}
            center={position}
            zoom={13}
            onClick={this.handleClick}
            onCreate={this.onCreate}
            onLocationfound={this.handleLocationFound}
          >
            <TileLayer
              attribution='&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
              url="http://{s}.tile.osm.org/{z}/{x}/{y}.png"
            />
            <FeatureGroup>
              <EditControl
                position="topleft"
                onEdited={this._onEditPath}
                onCreated={this.onCreate}
                onDeleted={this._onDeleted}
                onMounted={this._mounted}
                onEditStart={this._onEditStart}
                onEditStop={this._onEditStop}
                onDeleteStart={this._onDeleteStart}
                onDeleteStop={this._onDeleteStop}
                draw={{
                  rectangle: false,
                }}
              />
            </FeatureGroup>
            <Polygon color="purple" positions={polygon} />
            <GeoJSON
              data={london_postcodes}
              style={this.geoJSONStyle}
              onEachFeature={this.onEachFeature}
            />
          </Map>


}

Answer 1

我遇到了完全相同的问题，检查后想出了一个解决方案this post

因此，如果是多边形，您的绘图按钮应该有一个像这样的 onClick 事件：

const mapEvent =(e)=> {
    var e = document.createEvent('Event');
    e.initEvent('click', true, true);
    var cb = document.getElementsByClassName('leaflet-draw-draw-polygon');
    return !cb[0].dispatchEvent(e);
};

<button onClick={(e)=> {mapEvent(e)}}>
  Draw polygon
</button>

使用CSS隐藏默认工具栏按钮：

.leaflet-draw-draw-polygon {
  display: none !important;
}

您可以将此方法用于多个传单元素或操作，只需使用以下类而不是上面示例中的 leaflet-draw-draw-polygon：

折线：leaflet-draw-draw-polyline,
标记：leaflet-draw-draw-marker,
编辑：leaflet-draw-edit-edit,
删除：leaflet-draw-edit-remove,
等...

这不是最优雅的解决方案，但它有效并使我免于进一步的麻烦。

Answer 2

我个人使用 redux 来存储 leaflet map whenCreated 然后我就可以了

let drawShapeControl = new L.Draw.Polygon(leafletMap);

其中leafletMap是存储的地图。

如何在Leaflet中创建具有绘制多边形功能的按钮？

How to create button with function of draw polygons in Leaflet?

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leaflet.draw