// 初始化 featureGroup 用来放 editable layers
var editableLayers = new window.L.FeatureGroup();
map.addLayer(editableLayers);

// 插件的配置项。我这里只需要画折线，所以把其它几个开关都设为 false
var drawPluginOptions = {
  position: 'topright',
  draw: {
    polyline: {
      shapeOptions: {
        color: '#f357a1',
        weight: 2
      }
    },
    circle: false,
    polygon: false,
    rectangle: false,
    marker: false,
    circlemarker: false
  },
  edit: {
    featureGroup: editableLayers, // REQUIRED!!
    remove: false,
    edit: false  // 不显示 edit 图标
  }
}

// 利用上面的配置项初始化一个插件控制器
var drawControl = new window.L.Control.Draw(drawPluginOptions)
this.map.addControl(drawControl)

// 监听用户画完一个形状，把 layer 添加到地图
this.map.on('draw:created', function(e) {
  const layer = e.layer
  const latlngs = layer._latlngs
  console.log('points:', latlngs)  // 可以在这里得到画线所包含的坐标点
  editableLayers.addLayer(layer)
})