如何移除bs4Dash中tabCard顶部的多余小标签？

问题 #

使用bs4Dash开发Shiny应用时，在bs4TabCard中嵌套tabsetPanel后，组件顶部出现了一个无意义的多余小标签，希望通过调整组件布局而非CSS隐藏来解决。

解决方案 #

问题根源在于bs4TabCard本身是自带标签栏的容器组件，错误地在它内部嵌套完整的tabsetPanel，导致出现两层标签结构（bs4TabCard自带的空标签栏 + 内部的tabsetPanel标签栏）。

正确的做法是直接将顶层标签（Price、Volume等）作为bs4TabCard的直接子元素，无需外层的tabsetPanel，再在每个顶层标签内嵌套子级的tabsetPanel即可。

修改后的代码如下：

ui <- bs4Dash::bs4DashPage(
    header = bs4Dash::bs4DashNavbar(),
    sidebar = bs4Dash::bs4DashSidebar(disable = TRUE),
    body = bs4Dash::bs4DashBody(
        fluidPage(
            bs4Dash::bs4TabCard(
                width = 12,
                collapsible = FALSE,
                # 直接传入顶层tabPanel，无需外层tabsetPanel
                tabPanel("Price",
                         tabsetPanel(
                             id = "price_tabs",
                             tabPanel("Mandelbrot", "Content for Mandelbrot"),
                             tabPanel("Momentum", "Content for Momentum"),
                             tabPanel("Past Returns", "Content for Past Returns")
                         )
                ),
                tabPanel("Volume",
                         tabsetPanel(
                             id = "volume_tabs",
                             tabPanel("Momentum", "Content for Momentum"),
                             tabPanel("Historical", "Content for Historical")
                         )
                ),
                tabPanel("Volatility",
                         tabsetPanel(
                             id = "volatility_tabs",
                             tabPanel("Momentum", "Content for Momentum"),
                             tabPanel("IVOL/RVOL", "Content for IVOL/RVOL"),
                             tabPanel("Gross/Degross", "Content for Gross/Degross")
                         )
                ),
                tabPanel("Positioning",
                         tabsetPanel(
                             id = "positioning_tabs",
                             tabPanel("Put/Call/Ratio", "Content for Put/Call/Ratio"),
                             tabPanel("Short Interest", "Content for Short Interest"),
                             tabPanel("Number of Shares", "Content for Number of Shares")
                         )
                )
            )
        )
    ),
    controlbar = NULL,
    footer = NULL
)

server <- function(input, output, session) {
}

shinyApp(ui, server)

调整后，bs4TabCard的顶部标签栏会直接显示你定义的顶层标签，内部嵌套的子tabsetPanel也能正常工作，完全消除了多余的空标签。

内容的提问来源于stack exchange，提问作者JJ Fantini