如何在R Leaflet中设置默认仅显示单个Overlay分组而非全部？

要实现初始仅显示mex分组，只需把不需要默认展示的gtm分组对应的图层设置为初始不可见即可，具体通过pathOptions(visible = FALSE)参数控制：

修改后的完整代码如下：

library(raster)
library(leaflet)

#加载Shapefile文件
gtm <- getData('GADM', country = 'GTM', level = 0)
mex <- getData('GADM', country = 'MEX', level = 0)

leaflet() %>%
  addTiles() %>% 
  # 将gtm分组设为初始不可见
  addPolygons(data = gtm, 
              fillColor = 'red', 
              group = "gtm",
              options = pathOptions(visible = FALSE)) %>% 
  addLegend(color = "red",
             labels = gtm@data$GID_0, 
             group = "gtm",
             opacity = 1) %>% 
  
  addPolygons(data = mex,
              fillColor = 'blue',
              group = "mex") %>%
  addLegend(color = "blue",
            labels = mex@data$GID_0,
            group = "mex",
            opacity = 1) %>%

  addLayersControl(overlayGroups = c("gtm", "mex"), 
                   options = layersControlOptions(collapsed = F))

关键说明： #

• 在addPolygons(gtm)中添加options = pathOptions(visible = FALSE)，让该图层默认不显示
• 图例默认会同步对应分组的可见状态，无需额外设置图例的隐藏属性
• 给图例加上opacity = 1是为了让颜色显示更清晰，属于可选优化操作

页面加载后只会展示mex的图层和图例，用户可通过图层控制器切换显示gtm分组。

内容的提问来源于stack exchange，提问作者Ben Reid