In shinydashboard, 可以创建menuItem()s，是侧边栏中的选项卡。我希望能够使用标准轮询哪个选项卡处于活动状态input$foo syntax.

然而，我没能这样做。我尝试通过参考menuItem()'s tabName or id但这没有任何作用。

有办法做到吗？

sidebarMenu有可选的 id 参数，你可以使用它

sidebarMenu(id="menu1",
      menuItem("PointA_",tabName = "PointA") 
    )

在服务器端使用input$menu1

完整的工作示例，打印PointA or PointB（点击激活）

library(shiny)
library(shinydashboard)


ui <- dashboardPage(
  dashboardHeader(
    title = "Shiny"
  ),

  dashboardSidebar(
    sidebarMenu(id="sbmenu",
      menuItem("PointA_",tabName = "PointA") ,
      menuItem("PointB_",tabName = "PointB") 
    )
  ),

  dashboardBody(
    tabItems(
      tabItem("PointA",h1("a")),
      tabItem("PointB",h1("b"))
    )
  )
)


server <- function(input, output) {
  observe(print(input$sbmenu))
}

shinyApp(ui,server)

Update

找到一个 hack 变体来执行 active+ dropdown + input

使用附加功能（了解一下here https://github.com/rstudio/shinydashboard/issues/25 )

工作示例：

library(shiny)
library(shinydashboard)


convertMenuItem <- function(mi,tabName) {
  mi$children[[1]]$attribs['data-toggle']="tab"
  mi$children[[1]]$attribs['data-value'] = tabName
  if(length(mi$attribs$class)>0 && mi$attribs$class=="treeview"){
    mi$attribs$class=NULL
  }
  mi
}


ui <- dashboardPage(
  dashboardHeader(
    title = "Shiny"
  ),

  dashboardSidebar(
    sidebarMenu(id="sbmenu",
                convertMenuItem(menuItem("PointA_",tabName="PointA", selected=TRUE,

                                          checkboxInput("tc", "Test check", value=FALSE)
                         ),'PointA')        ,
                convertMenuItem(menuItem("PointB_",tabName="PointB",checkboxInput("tc2", "Test check", value=FALSE)
                ),'PointB') 
    )
  ),

  dashboardBody(


    tabItems(
      tabItem("PointA",h1("a")),
      tabItem("PointB",h1("b"))
    )
  )
)


server <- function(input, output) {

  observe({
    print(input$sbmenu)

    })


}

shinyApp(ui,server)

Bonus

我不知道有关儿童等的文件。

但如果你看看之间的差异 您可以看到 menuItem 和 menuItem+additionlal 元素：

aa=menuItem("PointA_",tabName="PointA", selected=TRUE,

         checkboxInput("tc", "Test check", value=FALSE)
)

aa1=menuItem("PointA_",tabName="PointA", selected=TRUE)

> aa
<li class="treeview">
  <a href="#shiny-tab-PointA">
    <span>PointA_</span>
    <i class="fa fa-angle-left pull-right"></i>
  </a>
  <ul class="treeview-menu">
    <div class="form-group shiny-input-container">
      <div class="checkbox">
        <label>
          <input id="tc" type="checkbox"/>
          <span>Test check</span>
        </label>
      </div>
    </div>
  </ul>
</li>
> aa1
<li>
  <a href="#shiny-tab-PointA" data-toggle="tab" data-value="PointA" data-start-selected="1">
    <span>PointA_</span>
  </a>
</li>

所以如你所见aa1 have data-toggle="tab" data-value="PointA"你需要它来添加到aa

但是aa有class="treeview"（我尝试在检查中删除此类以检查更改的内容）您需要删除它。

关于孩子，您可以在 Rstudio 的环境视图中看到