Shiny 我能'；t使用shinny在R studio上打印图像

我正在尝试使用shinny打印图像，但由于文件无效，无法工作。任何人都可以帮忙

输出：

str（文件名）中出错：计算参数“object”时出错 在为函数“str”选择方法时：错误：对象“filename”不是 发现

这是代码

installed.packages("shiny")
library(shiny)

shinyUI(fluidPage(

titlePanel(title="Omega Engineering and Design"),
sidebarLayout(position="left",
  sidebarPanel(
    selectInput("drawing","choose the section: ",choices=c("wall cross section","wall cross section 2"),selected = NULL)
   ),

     mainPanel(("Project Avalon"),
            imageOutput("drawing")  ))))
library(png)
library(shiny)


shinyServer(
  function(input,output,session){

 output$drawing=renderImage({

   filename=normalizePath(file.path('./images',paste('wall',input$drawing,'.png',sep='')))

   if(is.null(input$drawing))
     return(NULL)

   if(input$drawing=="wall cross section")
     return(
       list(
         scr= ("C:/Users/Darren Chu/Documents/images/images/wall1.png"),
     fileType="image/png",
         alt=paste("Wall Cross section", input$drawing)

       ))

   else if(input$drawing=="wall cross section 2")
     return(list(
       scr= ("C:/Users/Darren Chu/Documents/images/images/wall2.png"),
 fileType="image/png",
       alt=paste("Wall Cross section", input$drawing)

     ))  
 },deleteFile = F)})

---

调用

list（）

它应该是

src=…

，而不是

scr=…

该核心运行：

library(shiny)

ui <- fluidPage(
  titlePanel(title="Omega Engineering and Design"),
  sidebarLayout(position="left",
                sidebarPanel(
                selectInput("drawing","choose the section: ",choices=c("wall cross section","wall cross section 2"),selected = NULL)
                ),
                mainPanel(("Project Avalon"),
                          imageOutput("drawing")  )))


server <- function(input,output,session){
  output$drawing=renderImage({
    filename <- normalizePath(file.path('./images',paste('wall',input$drawing,'.png',sep='')))

    if(is.null(input$drawing))
      return(NULL)

    if(input$drawing=="wall cross section")
      return(
        list(
          src=("Test.png"),
          fileType="image/png",
          alt=paste("Wall Cross section", input$drawing)

        ))

    else if(input$drawing=="wall cross section 2")
      return(list(
        src= ("Test2.png"),
        fileType="image/png",
        alt=paste("Wall Cross section", input$drawing)

      ))  
  },deleteFile = F)}

shinyApp(ui, server)

库（闪亮）
用户界面
library(shiny)

ui <- fluidPage(
  titlePanel(title="Omega Engineering and Design"),
  sidebarLayout(position="left",
                sidebarPanel(
                selectInput("drawing","choose the section: ",choices=c("wall cross section","wall cross section 2"),selected = NULL)
                ),
                mainPanel(("Project Avalon"),
                          imageOutput("drawing")  )))


server <- function(input,output,session){
  output$drawing=renderImage({
    filename <- normalizePath(file.path('./images',paste('wall',input$drawing,'.png',sep='')))

    if(is.null(input$drawing))
      return(NULL)

    if(input$drawing=="wall cross section")
      return(
        list(
          src=("Test.png"),
          fileType="image/png",
          alt=paste("Wall Cross section", input$drawing)

        ))

    else if(input$drawing=="wall cross section 2")
      return(list(
        src= ("Test2.png"),
        fileType="image/png",
        alt=paste("Wall Cross section", input$drawing)

      ))  
  },deleteFile = F)}

shinyApp(ui, server)