R 更新下拉列表

我正在从数据库中提取一个列表，并尝试根据搜索结果更新该列表。我已经在这里提到了一些答案，但我还不能让它正常工作。这是我的密码：

ui.R

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

cxn <- odbcConnect("DSN", uid = "myID", pwd = "myPWD")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select Show", showList)

    ),

    # Show a plot of the generated distribution
    mainPanel(

    )
  )
))

 library(shiny)

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observeEvent(input$Search, function() {

    output$searchResults <- renderTable({
      searchResults()  
    })

    updateTextInput(session, "showDrop", "Select Show", searchResults())

  })

})

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

#cxn <- odbcConnect("DSN", uid = "myName", pwd = "myPwd")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select show", choices = showList),

    ),
  )
))

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observe({
    updateSelectInput(session, "showDrop", label = "Select show", choices =   searchResults())
  })

})

库（闪亮）
图书馆（RODBC）
图书馆（plyr）
图书馆（magrittr）
cxn%.[1]]>%as.字符（.）
shinyUI（fluidPage）(
#申请名称
标题面板（“选择显示数据”），
#带有滑块输入的边栏，用于输入箱子数量
侧边栏布局(
侧栏面板(
textInput（“名称搜索”、“按显示名称搜索”），
br（），
提交按钮（“搜索”），
br（），
选择输入（“显示下拉”、“选择显示”、显示列表）
),
#显示生成的分布图
主面板(
)
)
))

server.R

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

cxn <- odbcConnect("DSN", uid = "myID", pwd = "myPWD")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select Show", showList)

    ),

    # Show a plot of the generated distribution
    mainPanel(

    )
  )
))

 library(shiny)

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observeEvent(input$Search, function() {

    output$searchResults <- renderTable({
      searchResults()  
    })

    updateTextInput(session, "showDrop", "Select Show", searchResults())

  })

})

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

#cxn <- odbcConnect("DSN", uid = "myName", pwd = "myPwd")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select show", choices = showList),

    ),
  )
))

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observe({
    updateSelectInput(session, "showDrop", label = "Select show", choices =   searchResults())
  })

})

库（闪亮）
shinyServer（功能（输入、输出、会话）{
searchResults我会尝试使用动态用户界面。我不知道这是否可行，因为我无法复制它，但请尝试一下，让我知道会发生什么

用户界面

库（闪亮）
图书馆（RODBC）
图书馆（plyr）
图书馆（magrittr）
cxn%.[1]]>%as.字符（.）
shinyUI（fluidPage）(
#申请名称
标题面板（“选择显示数据”），
#带有滑块输入的边栏，用于输入箱子数量
侧边栏布局(
侧栏面板(
textInput（“名称搜索”、“按显示名称搜索”），
br（），
操作按钮（“搜索”），
br（），
uiOutput（“dynamicDropdown”）
),
#显示生成的分布图
主面板(
)
)
))

服务器.R

library(shiny)

cxn <- odbcConnect("DSN", uid = "myID", pwd = "myPWD")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyServer(function(input, output, session) {

  searchResults <- reactive({
     if(input$Search == 0) return(NULL)

    isolate(showList[grepl(input$nameSearch, showList, ignore.case = TRUE)])
  })

    output$dynamicDropdown <- renderUI({
     if(input$Search == 0) return(NULL)
     isolate(selectInput("showDrop", "Select Show", searchResults()))
    })

})

库（闪亮）
cxn%.[1]]>%as.字符（.）
shinyServer（功能（输入、输出、会话）{
searchResults由于RStudio添加了更新选择列表的功能，因此这个问题没有实际意义。我使用的是函数
updateSelectInput
。下面是代码供将来参考：

ui.R

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

cxn <- odbcConnect("DSN", uid = "myID", pwd = "myPWD")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select Show", showList)

    ),

    # Show a plot of the generated distribution
    mainPanel(

    )
  )
))

 library(shiny)

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observeEvent(input$Search, function() {

    output$searchResults <- renderTable({
      searchResults()  
    })

    updateTextInput(session, "showDrop", "Select Show", searchResults())

  })

})

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

#cxn <- odbcConnect("DSN", uid = "myName", pwd = "myPwd")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select show", choices = showList),

    ),
  )
))

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observe({
    updateSelectInput(session, "showDrop", label = "Select show", choices =   searchResults())
  })

})

库（闪亮）
图书馆（RODBC）
图书馆（plyr）
图书馆（magrittr）
#cxn%.[1]]>%as.字符（.）
shinyUI（fluidPage）(
#申请名称
标题面板（“选择显示数据”），
#带有滑块输入的边栏，用于输入箱子数量
侧边栏布局(
侧栏面板(
textInput（“名称搜索”、“按显示名称搜索”），
br（），
提交按钮（“搜索”），
br（），
选择输入（“显示下拉”、“选择显示”，选项=显示列表），
),
)
))

server.R

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

cxn <- odbcConnect("DSN", uid = "myID", pwd = "myPWD")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select Show", showList)

    ),

    # Show a plot of the generated distribution
    mainPanel(

    )
  )
))

 library(shiny)

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observeEvent(input$Search, function() {

    output$searchResults <- renderTable({
      searchResults()  
    })

    updateTextInput(session, "showDrop", "Select Show", searchResults())

  })

})

library(shiny)
library(RODBC)
library(plyr)
library(magrittr)

#cxn <- odbcConnect("DSN", uid = "myName", pwd = "myPwd")

showList <- sqlQuery(cxn, "my query string", believeNRows=FALSE) %>% arrange(., SERIES_NAME) %>% .[ ,1] %>% as.character(.)

shinyUI(fluidPage(

  # Application title
  titlePanel("Select Show Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(
    sidebarPanel(

      textInput("nameSearch", "Search by show name"),

      br(),

      submitButton("Search"),

      br(),

      selectInput("showDrop", "Select show", choices = showList),

    ),
  )
))

shinyServer(function(input, output, session) {

  searchResults <- reactive({
    showList[grepl(input$nameSearch, showList, ignore.case = TRUE)] 
  })

  observe({
    updateSelectInput(session, "showDrop", label = "Select show", choices =   searchResults())
  })

})

shinyServer（功能（输入、输出、会话）{
searchResults似乎不起作用。我得到了“错误：参数长度为零”的下拉框，错误：if中的错误（input$Search==0）return（NULL）：参数长度为零我自己能够让它工作，但感谢您的帮助。