根据滑块输入选择要在数据表中显示的行数

我正在尝试使用滑块输入选择要在数据表中显示的行数。

这是我的应用程序,页面长度为2

library(shiny)
library(DT)

# Dummy data 
dataset <- data.frame(lng = c(-5, -5, -5, -5, -15, -15, -10),
             lat = c(8, 8, 8, 8, 33, 33, 20),
             year = c(2018, 2018, 2018, 2017, 2017, 2017, 2016),
             type = c('A', 'A', 'A', 'A', 'B', 'B', 'A'),
             id =c("1", "1", "1", "1", "2", "2", "3"))


ui <- fluidPage(

  sidebarLayout(
  sidebarPanel(
     sliderInput("rows",
                 "Number of rows",
                 min = 1,
                 max = 50,
                 value = 1)
  ),

 # datable output 
     DT::dataTableOutput(outputId =  "table")
  )
 )
)

 server <- function(input, output) {



        output$table <- DT::renderDataTable(
            dat <- datatable(dataset,
                             options = list(
                               paging =TRUE,
                               pageLength =  2 
                               )
                             )
            )

        }

        # Run the application 
        shinyApp(ui = ui, server = server)

我在服务器端的尝试: 一。首先,我试着用 sliderInput$rows 作为pageLength的参数: pageLength = sliderInput$rows

2. 我还尝试了服务器端:

    server <- function(input, output) {
   
     i <- reactive({sliderInput$rows})
   
     output$table <- DT::renderDataTable(
       dat <- datatable(dataset,
                        options = list(
                          paging =TRUE,
                          pageLength =  i() 
                        )
       )
     )
   
   }