按下“测试垃圾箱”按钮应该引起后observeEvent功能打印出30和随后的25和35滑块更新后,但30之前和之后被重复打印updateSliderInput的。由于某些原因,observeEvent代码似乎不处理滑块输入中的更改。更新输入功能不生效,直到observeEvent
ui.R:
library(shiny)
shinyUI(fluidPage(
titlePanel("Old Faithful Geyser Data"),
sidebarLayout(
sidebarPanel(
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30),
actionButton("test","Test Bins")
),
mainPanel(
plotOutput("distPlot")
)
)
))
server.R:
library(shiny)
shinyServer(function(input, output, session) {
output$distPlot <- renderPlot({
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
observeEvent(input$test,{
print(input$bins)
updateSliderInput(session,"bins",value=25)
print(input$bins)
updateSliderInput(session,"bins",value=35)
print(input$bins)
})
})
'input $ bins'在当前'observeEvent()'中没有反应。在'$输入一个bins'单独'observeEvent'会前和击中按钮后,打印值。说得通?? – Sagar