![错误在哪里?#1 在 \caption 里面](https://linux22.com/image/330708/%E9%94%99%E8%AF%AF%E5%9C%A8%E5%93%AA%E9%87%8C%EF%BC%9F%231%20%E5%9C%A8%20%5Ccaption%20%E9%87%8C%E9%9D%A2.png)
我正在尝试自动转换\caption{...\label{...}...}
为\caption{...}\label{...}
。这是我尝试过的:
\documentclass{article}
\usepackage{showlabels}
\newcommand{\storelabel}[1]{\gdef\storedlabel{#1}}
\let\oldcaption\caption
\renewcommand{\caption}[1]{%
\let\storedlabel\undefined
\oldcaption{%
\def\label##1{%
\protect\storelabel{##1}%
}%
#1%
}%
\ifdefined\storedlabel%
\label{\storedlabel}%
\else%
\fi%
}
\begin{document}
\begin{table}
\caption{no label}
foo
\end{table}
\begin{table}
\caption{\label{mylabel}label inside caption (front)}
foo
\end{table}
\begin{table}
\caption{label inside caption (back) \label{mylabel}}
foo
\end{table}
\begin{table}
\caption{label directly after caption}
\label{mylabel}
foo
\end{table}
\begin{table}
\caption{label at end of table (I'm OK with that one)}
foo
\label{mylabel}
\end{table}
\end{document}
pdf 文件看起来也正确,但我收到此错误消息(五次,每次调用一次\caption
):
! Illegal parameter number in definition of \reserved@a.
<to be read again>
1
l.20 \caption{no label}
You meant to type ## instead of #, right?
Or maybe a } was forgotten somewhere earlier, and things
are all screwed up? I'm going to assume that you meant ##.
如果我\storelabel{##1}
用替换\storelabel{mylabel}
,pdf 文件看起来一样,错误消息也消失了。但这显然不是我想要的。
更新:这个 MWE 很好地显示了同样的错误,\label
虽然这与我最初搬出\caption
并因此移动showlabels
标签的目标无关。
\documentclass{article}
\begin{document}
\begin{table}
\caption{\def\foo[#1]{#1}}
\end{table}
\end{document}
答案1
在我看来,最好是捕获\label
并让其将标签名称存储\storedlabel
在中,然后在发出后将\caption
实际移至\label
的末尾。\@caption
\@makecaption
重新定义\label
will breakcleveref
的\label[...]{foo}
风格!
\documentclass{article}
\usepackage{showlabels}
\usepackage{xparse}
\usepackage{letltxmacro}
\usepackage{xpatch}
\usepackage{cleveref} % Just for testing!
\makeatletter
\LetLtxMacro\latex@@origlabel\label
\xpatchcmd{%
\caption
}{%
\refstepcounter\@captype%
}{%
\let\storedlabel\undefined%
\refstepcounter\@captype
\begingroup
\renewcommand{\label}[1]{%
\gdef\storedlabel{##1}% Catch the the label but doing nothing except of storing it!
}
\endgroup
}{\typeout{Successfully patched caption}}{\typeout{Failed in patching caption}}
\xpatchcmd{\@caption}{%
\@makecaption{\csname fnum@#1\endcsname}{\ignorespaces #3}\par
\endgroup}{%
\@makecaption{\csname fnum@#1\endcsname}{\ignorespaces #3}\par
\endgroup%
\@ifundefined{storedlabel}{}{% Transfer the label to this place
\label@@origlabel{\storedlabel}}%
}{\typeout{Success}}{\typeout{Failure!}}
\makeatother
\begin{document}
\begin{table}
\caption{no label}
foo
\end{table}
\begin{table}
\caption{\label{othermylabel}label inside caption (front)}
foo
\end{table}
\begin{table}
\caption{label inside caption (back) \label{mylabel}}
foo
\end{table}
\begin{table}
\caption{label directly after caption}
\label{mylabelfoo}
foo
\end{table}
\begin{table}
\caption{label at end of table (I'm OK with that one)}
foo
\label{mylabelfoobar}
\end{table}
Now some referencing: \cref{othermylabel} and \ref{mylabel} and \ref{mylabelfoo} and \ref{mylabelfoobar}
\end{document}
答案2
这有效:
\documentclass{article}
%\usepackage{caption}
\usepackage{showlabels}
\usepackage{xpatch}
\def\storelabel#1{\gdef\storedlabel{#1}}
\makeatletter
\patchcmd{\@caption}{#3}{\global\let\storedlabel\undefined\let\label\storelabel#3}{}{err}
\apptocmd{\@caption}{\ifdefined\storedlabel\label{\storedlabel}\else\fi}{}{err}
\makeatother
\begin{document}
\listoftables
\clearpage
\begin{table}
\caption{no label}
foo
\end{table}
\begin{table}
\caption{\label{mylabel}label inside caption (front)}
foo
\end{table}
\begin{table}
\caption{label inside caption (back) \label{mylabel}}
foo
\end{table}
\begin{table}
\caption{label directly after caption}
\label{mylabel}
foo
\end{table}
\begin{table}
\caption{label at end of table (I'm OK with that one)}
foo
\label{mylabel}
\end{table}
\end{document}
主要区别在于
\def\label##1{...}
-> ,避免\let\label\storelabel
使用##1
\caption
- 受到@ChristianHupfer 的启发并感谢他,使用 来
xpatch
选择性修补\@caption
而不是重新定义\caption
。它甚至可以与caption
包和\listoftables
now 一起使用。
他的评论仍然有效:\label
使用可选参数失败。但我不需要那个。