如何在 Leaflet for R 中基于 addLayerControl() 隐藏/切换图例 [英] How to hide/toggle legends based on addLayerControl() in Leaflet for R

问题描述

我想知道如何在 Leaflet for R 中基于 addLayerControl() 隐藏/切换图例?当option层A被切换时，选项层B的数据不会被AddPolygons()显示，因为我可以使用组.但是，addLegend() 选项没有 GROUP 功能，所以当我选择图层组 a(红色)时，我无法隐藏图层组 b(蓝色)的图例:

I'm wondering how to hide/toggle legends based on addLayerControl() in Leaflet for R? When option layer a is toggled, then the data of option layer b is not showed by addPolygons() because I can use GROUP. However, the addLegend() option doesn't have the GROUP functionality so I'm not able to hide the legend of group layer b(blue) when I selected group layer a(red):

来源:https://gis.stackexchange.com/questions/214773/how-to-hide-toggle-legends-with-layer-controls-in-leaflet-for-r

你知道怎么做吗?

问候，

乔里斯

推荐答案

万一以后有人看这个，有一个新的可行方法.

In case anyone is looking at this in the future, there's a new viable method.

如果您使用的是 leaflet 包的开发/Github 版本，addLegend() 现在支持 group 和 layerId 参数.

If you're using the development/Github version of the leaflet package, addLegend() now supports the group and layerId arguments.

(运行命令devtools::install_github('rstudio/leaflet')进行安装)

即使是最新的 CRAN 版本 (1.1.0) 也支持 layerID.

Even the latest CRAN version (1.1.0) supports layerID.

假设您使用开发版本，以下代码应该可以工作:

Assuming you go with the development version, the following code should work:

leaflet() %>%
    #Polygon Layers
    addPolygons(data = exampleDataOne, group = "Group A") %>%
    addPolygons(data = exampleDataTwo, group = "Group B") %>%

    #Legend Layers
    addLegend(values = exampleValuesOne, group = "Group A", 
              position = "bottomright") %>%
    addLegend(values = exampleValuesTwo, group = "Group B",
              position = "bottomright") %>%

    #Layers Control
    addLayersControl(overlayGroups = c("Group A","Group B"),
              options = layersControlOptions(collapsed = FALSE))

这应该具有仅在相应图层处于活动状态时才显示图例的预期效果.

This should have the desired effect of only displaying a legend when the corresponding layer is active.

一个潜在的问题是，默认情况下，所有 leaflet 层都是活动的.如果您有重叠的多边形，这可能会导致地图的视觉吸引力降低.而且，如果您有多个图例，这也是一个问题.

One potential issue is that by default, all leaflet layers are active. If you have overlapping polygons, this can lead to a less visually appealing map. And, if you have multiple legends, this will also be an issue.

你可以做的是使用 hideGroup() 函数.

What you can do is use the hideGroup() function.

如果您只想让上述示例中的 Group A 在开始时处于活动状态，则可以添加

If you wanted to have only Group A from the above example active at start, you could add

%>% hideGroup("Group B")

到上面代码块的末尾.

这篇关于如何在 Leaflet for R 中基于 addLayerControl() 隐藏/切换图例的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！