您的ui代码很好，但是：

Your ui code is fine, but:

Shiny不支持相同的多个输出名称。此代码
将生成HTML，其中两个元素具有相同的ID，即
无效HTML。

Shiny doesn't support multiple outputs with the same name. This code would generate HTML where two elements have the same ID, which is invalid HTML.

，我认为您唯一的解决方案是创建第三个表。***的选择是在中间使用反应式，这样可以避免两次使用相同的代码。

So, I think your only solution would be to create a third table. The best option is to use a reactive in the middle, so you avoid having the same code used twice.

function(input, output) {

  # display 10 rows initially
  output$ex1 <- DT::renderDataTable(
    DT::datatable(iris, options = list(pageLength = 25))
  )

  # -1 means no pagination; the 2nd element contains menu labels

  iris_table <- reactive({
    DT::datatable(
      iris, options = list(
        lengthMenu = list(c(5, 15, -1), c('5', '15', 'All')),
        pageLength = 15
      )
    )
  })

  output$ex2 <- DT::renderDataTable(
    iris_table()
  )
  output$ex3 <- DT::renderDataTable(
    iris_table()
  )

}

希望这会有所帮助！