如何在适用于pdf和html输出的bookdown文档中的表格标题中插入引用(How to insert a reference in a table caption in a bookdown document that works for both pdf and html output)

 我使用bookdown来生成html和pdf文档。 如何在表格的标题中插入对文档部分的引用？ 
 
 使用\\ref{sec:FirstSection}可以正常使用pdf_book（但不是gitbook）： 
 
---
title: "Test"
output: bookdown::pdf_book
---

# A section {#sec:FirstSection}
The dataset in Table \@ref(tab:aTable) contains some data.

# Another section
```{r, aTable, echo = FALSE}
knitr::kable(
  cars[1:5, ],
  caption  = "See Section \\ref{sec:FirstSection}."
)
```
 
 使用\\@ref(sec:FirstSection)可以正常使用gitbook（但不是pdf_book） 
 
---
title: "Test"
output: bookdown::gitbook
---

# A section {#sec:FirstSection}
The dataset in Table \@ref(tab:aTable) contains some data.

# Another section
```{r, aTable, echo = FALSE}
knitr::kable(
  cars[1:5, ],
  caption  = "See Section \\@ref(sec:FirstSection)."
)
    ```

I use bookdown to generate a document in both html and pdf. How could I insert a reference to a section of the document in the caption of a table?
 
Using \\ref{sec:FirstSection} works fine with pdf_book (but not gitbook):
 
---
title: "Test"
output: bookdown::pdf_book
---

# A section {#sec:FirstSection}
The dataset in Table \@ref(tab:aTable) contains some data.

# Another section
```{r, aTable, echo = FALSE}
knitr::kable(
  cars[1:5, ],
  caption  = "See Section \\ref{sec:FirstSection}."
)
```
 
whilst using \\@ref(sec:FirstSection) works fine with gitbook (but not pdf_book)
 
---
title: "Test"
output: bookdown::gitbook
---

# A section {#sec:FirstSection}
The dataset in Table \@ref(tab:aTable) contains some data.

# Another section
```{r, aTable, echo = FALSE}
knitr::kable(
  cars[1:5, ],
  caption  = "See Section \\@ref(sec:FirstSection)."
)
    ```

原文：https://stackoverflow.com/questions/46670422