如何将闪亮的表转换为data.frame

Question

我尝试使用nrow（）函数获取在Shiny中上载的表的行数，但是它不起作用。它确实与我手动创建的data.frame一起工作。谁能告诉我该怎么做？

这是我的代码：

library(shiny)


ui <- fluidPage(

    # Sidebar with a slider input for number of bins 
    sidebarLayout(
        sidebarPanel(
            fileInput("file1", "Upload File",
                      multiple = FALSE,
                      accept = c("text/csv",
                                 "text/comma-separated-values,text/plain",
                                 ".csv")),
        ),
        mainPanel(
            p("Number of Rows:"),    
            textOutput("rowNumber")
        )
    )
)


server <- function(input, output) {

    myTable <- reactive({
        req(input$file1)
        tryCatch(
            {
                df <- read.csv(input$file1$datapath,
                               header = TRUE,
                               sep = ",",
                               quote = '"')
            },
            error = function(e) {
                stop(safeError(e))
            }
        )
        return(df)
    })

    myTable2 <- data.frame(c(1, 2), c(2, 3))

    output$rowNumber <- renderText({
        nrow(myTable)
        nrow(myTable2)
        })
}

shinyApp(ui = ui, server = server)