当用户在闪亮的应用程序 - R语言上更改输入时，如何在侧栏面板上添加更改

我希望你的第一个闪亮的应用程序，

实际上我想在用户更改选择输入时在侧栏面板上添加一些更改 .

例如，对于我的以下代码：

当用户选择choice3时，我想要闪亮的显示4文件输入，使用户能够添加4个文件，当用户选择复杂或super_complex时，默认将是2个文件输入，

我怎么能在R中应用它？

Ui.R

library(shiny)
library(shinythemes)
library(readxl)
library(dplyr)

options(error = traceback)


shinyUI(fluidPage(
theme=shinytheme("flatly"),
themeSelector(),
navbarPage(
title="My shiny App",
id="nav"),
sidebarLayout(
sidebarPanel(
  selectInput(
    "TFType",
    "Select one of the following" ,
    c("complex calc"="complex", "super complex calc"="super_complex" , "choice3")
  ),
 # tags$hr(),
  fileInput(
    "file1" ,
    tableOutput("inputType"),
    multiple = FALSE
  ),
 # tags$hr(),
  fileInput(
    "file2" ,
    tableOutput("inputType2"),
    multiple = FALSE
  ),
 verbatimTextOutput(" output$choice3"),
  # numericInput("obs", "Number of observations to view:", 10),
  actionButton("act" , "Calculate"),
  downloadButton("downloadData", "Download")

),
mainPanel(tabsetPanel(
  tabPanel("Data",     DT::dataTableOutput("contents") , tableOutput("view")) 
   ,
  tabPanel("Summary Data",DT::dataTableOutput("complex_calc")),
  tabPanel("plots" , verbatimTextOutput("datadownload"))

))
)
))

Server.R

server <- function(input, output) {

 options(shiny.maxRequestSize = 200*1024^2)

 df <- reactive({
 req(input$file1)

 tryCatch({
  df <- readxl::read_xlsx(input$file1$datapath, 1)
  },
  error = function(e) {
   stop(safeError(e))
  })
 })

  df_CBU <- reactive({
   req(input$file2)

   tryCatch({
     df_CBU <- readxl::read_xlsx(input$file2$datapath, 1)
    },
    error = function(e) {
     stop(safeError(e))
    })
   })

   output$contents <- DT::renderDataTable({
    df()

   })

    output$summary <- renderPrint({
           summary(input$file1 , as.numeric(input$file1))


     })
      calcuation <- eventReactive(input$act, {
      if (input$TFType == "complex") {
         complex_calc2(df(),df_CBU())
     }
      else if (input$TFType == "super_complex") {
         complex_calc3(df(),df_CBU())
        }

       else if (input$TFType == "choice3") {
        complex_calc4(df(),df_CBU())
         }
       })

         output$complex_calc <- DT::renderDataTable({
        calcuation()


      })

   output$downloadData <- downloadHandler(
     filename = function() {
        paste(input$file1, ".csv", sep = "")
        },
     content = function(file) {
      write.csv(calcuation(), file, row.names = FALSE )
       }
       )

       output$inputType <- renderText( {

      if ( input$TFType == "complex")
         "Upload File1"
     else if ( input$TFType == "super_complex")
            "Upload File2"
         else if ( input$TFType == "choice3")
             "Upload Mapping Files"
           })

          output$inputType2 <- renderText( {

         if ( input$TFType == "complex")
       "Upload File3"
      else if ( input$TFType == "super_complex")
          "Upload FileFile2"

          })

        # output$choice3 <- renderUI ( {

      # if (input$TFType == "choice3") {
       #   fileInput(
       #     "file3" ,
       #      tableOutput("inputType"),
     #      multiple = FALSE
     #     )
        # tags$hr(),
    #      fileInput(
   #        "file4" ,
    #        tableOutput("inputType2"),
      #        multiple = FALSE
     #    )
         #  }

     # }) 

   }

提前致谢