Shiny 从侧边栏菜单和单选按钮中选择时不显示图表

我不知道为什么没有显示图表。我所需要的只是用户必须从侧边栏菜单中选择一个菜单项并在单选按钮中选择一个选项，当选择这些菜单项时，必须显示仪表板主体中的相应选项卡。当我试图执行这段代码时，没有任何工作，也没有抛出错误。请帮忙。还建议是否可以使用其他编码来完成此操作。 谢谢

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ui如果您希望看到4个不同的选项卡及其自己的绘图，请定义四个反应性绘图。
然后在每个选项卡中，您有两个选择。
请参阅下面的代码

 ui <-  dashboardPage(#skin="purple-light",
    dashboardHeader(title="Testing"),
    dashboardSidebar(width=200, 
                     sidebarMenu(id= "sbar",verbatimTextOutput("text1"),verbatimTextOutput("text2"),
                                 menuItem("Menu1", tabName = "MenuTab1",startExpanded = TRUE,
                                          menuSubItem("Sub Menu1", tabName = "sub1"),
                                          menuSubItem("Sub Menu2", tabName = "sub2")),
                                 menuItem("Menu2", tabName= "MenuTab2",startExpanded = TRUE,
                                          menuSubItem("Sub Menu3", tabName = "sub3"),
                                          menuSubItem("Sub Menu4", tabName = "sub4")))),
    
    dashboardBody(radioButtons("rb1",label=NULL, choices = c("choice1","choice2"), selected=NULL),
                  tabItems(
                    tabItem("sub1",title= "Tab1",fluidRow(plotOutput("plot1"))),
                    tabItem("sub2",title= "Tab2",fluidRow(plotOutput("plot2"))),
                    tabItem("sub3",title= "Tab3",fluidRow(plotOutput("plot3"))),
                    tabItem("sub4",title= "Tab3",fluidRow(plotOutput("plot4")))
                    ))) 
  
  server <- function(input,output){
    set.seed(1234)
    observe(input$sbar)
    p1 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (      input$sbar == "sub1" && input$rb1 =="choice1" ){
        return(qplot(rnorm(500),fill=I("blue"),binwidth=0.2))
      }else if (input$sbar == "sub1" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("red"),binwidth=0.2))
      }
    })
    p2 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (input$sbar == "sub2" && input$rb1 =="choice1") {
        return(qplot(rnorm(500),fill=I("green"),binwidth=0.2))
      }else if (input$sbar == "sub2" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("brown"),binwidth=0.2))
      }
    })
    p3 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (      input$sbar == "sub3" && input$rb1 =="choice1" ){
        return(qplot(rnorm(500),fill=I("yellow"),binwidth=0.2))
      }else if (input$sbar == "sub3" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("orange"),binwidth=0.2))
      }
    })
    p4 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (input$sbar == "sub4" && input$rb1 =="choice1") {
        return(qplot(rnorm(500),fill=I("purple"),binwidth=0.2))
      }else if (input$sbar == "sub4" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("black"),binwidth=0.2))
      }
    })
    
    
    observe(input$sbar)
    output$text1      <- renderText(print(input$rb1))
    output$text2      <- renderText(print(input$sbar))
    output$plot1 <- renderPlot({p1()})
    output$plot2 <- renderPlot({p2()})
    output$plot3 <- renderPlot({p3()})
    output$plot4 <- renderPlot({p4()})
  }
  
  shinyApp(ui = ui, server = server)  

ui我确实按照您的建议进行了更改，但尚未绘制图表，也看不到逐字输出（text1）或text2。事实上，我需要使用menuSubItem和radioButton值来显示标题为tab1或tab2或tab3或tab4的tabItem。。。。在仪表板主体中。这些选项卡中的每一个都具有实时的fluidRows和多个图表。因此，如果我使用上述建议，这将只满足dashboarBody中的tab1选择。如何使用if条件显示所需的选项卡，而不是仅显示一个选项卡（即tab1）。请帮忙。
 ui <-  dashboardPage(#skin="purple-light",
    dashboardHeader(title="Testing"),
    dashboardSidebar(width=200, 
                     sidebarMenu(id= "sbar",verbatimTextOutput("text1"),verbatimTextOutput("text2"),
                                 menuItem("Menu1", tabName = "MenuTab1",startExpanded = TRUE,
                                          menuSubItem("Sub Menu1", tabName = "sub1"),
                                          menuSubItem("Sub Menu2", tabName = "sub2")),
                                 menuItem("Menu2", tabName= "MenuTab2",startExpanded = TRUE,
                                          menuSubItem("Sub Menu3", tabName = "sub3"),
                                          menuSubItem("Sub Menu4", tabName = "sub4")))),
    
    dashboardBody(radioButtons("rb1",label=NULL, choices = c("choice1","choice2"), selected=NULL),
                  tabItems(
                    tabItem("sub1",title= "Tab1",fluidRow(plotOutput("plot1"))),
                    tabItem("sub2",title= "Tab2",fluidRow(plotOutput("plot2"))),
                    tabItem("sub3",title= "Tab3",fluidRow(plotOutput("plot3"))),
                    tabItem("sub4",title= "Tab3",fluidRow(plotOutput("plot4")))
                    ))) 
  
  server <- function(input,output){
    set.seed(1234)
    observe(input$sbar)
    p1 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (      input$sbar == "sub1" && input$rb1 =="choice1" ){
        return(qplot(rnorm(500),fill=I("blue"),binwidth=0.2))
      }else if (input$sbar == "sub1" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("red"),binwidth=0.2))
      }
    })
    p2 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (input$sbar == "sub2" && input$rb1 =="choice1") {
        return(qplot(rnorm(500),fill=I("green"),binwidth=0.2))
      }else if (input$sbar == "sub2" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("brown"),binwidth=0.2))
      }
    })
    p3 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (      input$sbar == "sub3" && input$rb1 =="choice1" ){
        return(qplot(rnorm(500),fill=I("yellow"),binwidth=0.2))
      }else if (input$sbar == "sub3" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("orange"),binwidth=0.2))
      }
    })
    p4 <- reactive({
      req(input$rb1)
      req(input$sbar)
      
      if (input$sbar == "sub4" && input$rb1 =="choice1") {
        return(qplot(rnorm(500),fill=I("purple"),binwidth=0.2))
      }else if (input$sbar == "sub4" && input$rb1 =="choice2") {
        return(qplot(rnorm(500),fill=I("black"),binwidth=0.2))
      }
    })
    
    
    observe(input$sbar)
    output$text1      <- renderText(print(input$rb1))
    output$text2      <- renderText(print(input$sbar))
    output$plot1 <- renderPlot({p1()})
    output$plot2 <- renderPlot({p2()})
    output$plot3 <- renderPlot({p3()})
    output$plot4 <- renderPlot({p4()})
  }
  
  shinyApp(ui = ui, server = server)