为什么\@ref()符号无法与投影仪演示一起操作？

下面的问题可能会提醒您在编写PDF文档时交叉引用的一些问题，例如：this，但是当我进行投影仪演示时，答案中介绍的方法对我没有帮助。

现在我很困惑因为\@ref(fig:label-to-refer-figure) and \@ref(tab:label-to-refer-table)当我编织时，引用图形/表格的符号不起作用.Rmd带有选项的文件output: beamer_presentation。如下图所示，交叉引用的原始代码出现在输出的 PDF 文件中，但我无法引用图/表编号。尽管即使在列出的环境以及纯文本字段中，引文也能顺利进行，但图/表编号的交叉引用无法正确生效。

我的环境

• R版本3.5.1 (2018-07-02)
• 平台：x86_64-w64-mingw32/x64（64位）
• 运行环境：Windows 10 x64（内部版本 17134）
• knitr_1.20
• rmarkdown_1.10
• RStudio v1.2.1206（预览版）这个原因

MWEs

我在此处发布的 MWE 是根据以下来源创建的：test-beamer.Rmd and myref.bib.

test-beamer.Rmd

---
title: "Test"
subtitle: |
  | subtitle,
  | with a line break
author: |
  | CLR
  | Rafael
institute: |
  | Now I'm here,
  | Now I'm there
date: "`r format(Sys.time(), '%Y/%b/%d')`" #English
output: 
  beamer_presentation:
    keep_tex: yes
    latex_engine: lualatex
    theme: "AnnArbor"
    colortheme: "dolphin"
    fonttheme: "structurebold"
    toc: true
    #toc_depth: 3
    #number_sections: TRUE
    fig_caption: TRUE
    dev: cairo_pdf
    #extra_dependencies: subfig
    citation_package: natbib
    slide_level: 2 
bibliography: bibs/myref.bib
biblio-style: apa
always_allow_html: yes
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)
```

## The only thing

With Table \@ref(tab:under-pressure-table), @test-master shows that Figure \@ref(fig:under-pressure) depicts...

## Slide with Bullets in which I want to refer a figure

- \@ref(fig:under-pressure)
- @test-master
- \@ref(tab:under-pressure-table)

## Slide with R Output

```{r cars, echo = TRUE}
summary(cars)
```

## Slide with Plot

```{r under-pressure, fig.cap='Under Pressure', fig.pos='h', out.width="0.75\\textwidth"}
plot(pressure)
```

## Slide with Table

```{r under-pressure-table, caption = "This is a table"}
knitr::kable(pressure)
```

## More extraordinary

With Table \@ref(tab:under-pressure-table), @test-master shows that Figure \@ref(fig:under-pressure) depicts...

编辑：我添加了fig.cap='Under Pressure', fig.pos='h', out.width="0.75\\textwidth"到图形块，并且caption = "This is a table" to the knitr::kable()。如果没有这些代码，标题和表格/图号都不会出现...但是，即使将它们提供给整个系统，问题仍然存在.Rmd文件，除非你执行@Yihui的回答。

myref.bib

@master{test-master,
author = {Freddie Mercury and Brian May and John Deacon and Roger Taylor},
title = {Bohemian {R}hapsody: {W}e are the champions},
school = {{Queen}},
year = {2018},
address = {London}
}

The \@ref()符号的一个特点是bookdown仅有的。要将此功能移植到一般 R Markdown 文档，您可以设置base_format某个选项的bookdown输出格式，例如

output:
  bookdown::pdf_book:
    base_format: rmarkdown::beamer_presentation

See 第 3.4 节bookdown book了解详情。

适合此问题的 MWE 的完整 yaml 部分可能如下所示：

---
title: "Test"
subtitle: |
  | subtitle,
  | with a line break
author: |
  | CLR
  | Rafael
institute: |
  | Now I'm here,
  | Now I'm there
date: "`r format(Sys.time(), '%Y/%b/%d')`" #English
output:
  bookdown::pdf_book:
    base_format: "function(..., number_sections) rmarkdown::beamer_presentation(...)"
    number_sections: true
    keep_tex: yes
    latex_engine: lualatex
    theme: "AnnArbor"
    colortheme: "dolphin"
    fonttheme: "structurebold"
    toc: true
    fig_caption: TRUE
    dev: cairo_pdf
    #extra_dependencies: subfig
    citation_package: natbib
    slide_level: 2     
bibliography: bibs/myref.bib
biblio-style: apa
always_allow_html: yes
---