单击操作按钮时运行特定代码块

Question

我正在尝试在 R Markdown 中创建一个 flexdashboard，它在单击操作按钮时运行特定的代码块。 IE。在仪表板的开头，会出现一个带有单选按钮的问卷，而当单击“提交答案”按钮时，问卷应该会消失，并且会出现一个文本。目前，当我点击提交按钮时没有任何反应。我做错了什么？

这是我到目前为止尝试过的：

---
title: "Questionnaire"
output: 
  flexdashboard::flex_dashboard:
    orientation: rows
    vertical_layout: scroll
    css: www/styles.css
runtime: shiny
---
```{r setup, include=FALSE}
library(flexdashboard)
library(readxl)
library(openxlsx)
library(janitor)
library(data.table)
library(plotly)
library(shiny)
library(ggplot2)
library(rmarkdown)
library(CssDwhSpark)
library(tidyverse)
library(tibble)
library(shinydashboard)
library(DT)
library(shinyWidgets)
library(editData)
library(knitr)
```
```{r}
eval1 = reactiveVal(TRUE)
eval2 = reactiveVal(FALSE)

observeEvent(input$submit, {
  isolate(eval1(FALSE))
  isolate(eval2(TRUE))
  })
```
```{r, chunk1, eval = eval1()}
asis_output("## Row\n### Satisfaction\nHow satisfied are you with the     service?\n")

fluidPage(
radioButtons(
inputId = "answer1",
label = NULL,
choices = c("Very satisfied", "Satisfied", "Not satisfied"),
selected = character(0),
width = '100%'
))

asis_output("## Row\n### Recommandation\nHow probable is it that you would recommend our service?\n")

fluidPage(
radioButtons(
inputId = "answer2",
label = NULL,
choices = c("Very probable", "Probable", "Not probable"),
selected = character(0),
width = '100%'
))

asis_output("## Row\n")
fluidPage(
  actionButton(inputId = "submit", label = "Submit Answers")
)

```
```{r, chunk2, eval = eval2()}
asis_output("## Row\n")
h4("Thank you for filling up our questionnaire!")
```