ipy传单draw_control不处理"clear all"按钮

Question

我正在使用ipyleaflet中的draw_control函数在地图上绘制多边形。我正在收集我使用feature_collection变量绘制的内容，它运行良好。但是，当我在映射的bin按钮上按下clear all时，feature_collection变量不会被清空——我如何将映射上按下的clear all按钮转换为清除我的feature_collection变量？目前它复制了我以前画的，所以我有这样的工作流程：

1. 绘制两个多边形
2. feature_collection包含关于两个ploygon的信息
3. 按地图上bin按钮上的clear all
4. 在地图上绘制两个新多边形
5. feature_collection现在包含6(！(个条目，与1重复。动作两次

这里有一个要复制的代码！基本上，我不知道如何从bin按钮收集clear_all操作来清除我的feature_control变量。

from ipyleaflet import Map, basemaps, basemap_to_tiles, DrawControl, LayersControl, GeoJSON, SearchControl, Marker, FullScreenControl

#Creating empty geojson to collect features drawn on map: 
feature_collection = {
'type': 'FeatureCollection',
'features': []}
#Handling items drawn on map: 
def handle_draw(self, action, geo_json):
"""Do something with the GeoJSON when it's drawn on the map"""    
feature_collection['features'].append(geo_json)

#Generate Basemap: 
satellite = basemap_to_tiles(basemaps.Esri.WorldImagery)
osmap = basemap_to_tiles(basemaps.OpenStreetMap.Mapnik)
mymap = Map(layers=(osmap, satellite), center=(55,0), zoom=5,scroll_wheel_zoom=True)
#Generate controls on map:
center=[55,0] #where to start on map: middle of UK
marker = Marker(location=center, draggable=False)
#Draw shapes on map: 
dc = DrawControl(
marker={'shapeOptions': {'color': '#0000FF'}},
rectangle={'shapeOptions': {'color': '#0000FF'}},
circlemarker={}
)
dc.on_draw(handle_draw) #call function what to do with objects drawn on maps
#Add all controls to the actual map: 
mymap.add_control(dc) #add 
#Generate GEOJSON which could contain data to be displayed on map: 
geo_json = GeoJSON(data={},style={},hover_style={})

mymap.add_layer(geo_json) #add to map object
mymap 

Answer 1

在handle_draw方法中，您不仅有geo_json功能，还有一个action参数，可以帮助您处理DrawingControl中发生的事情。

清除时，action将为deleted。

因此，要调整您的代码，您可以执行以下操作：

#Handling items drawn on map: 
def handle_draw(self, action, geo_json):
"""Do something with the GeoJSON when it's drawn on the map""" 
if action in ['created', 'edited']:
feature_collection['features'].append(geo_json)
elif action == 'deleted':
feature_collection['features'].remove(geo_json)
return 

注意，由于"编辑"没有提供任何关于原始形状的信息，您不知道修改的是哪一个