我一直在关注解决方案这里让 tikzcd 和外部化库彼此之间能够很好地协作。
其中一个步骤是重新定义&。但是，目前，它对整个文档执行此操作，而我希望它只对环境执行此操作mytikzcd。我尝试将代码移到mytikzcd定义中，但根据我将其放置的具体位置，我似乎会收到各种不同的错误。您有什么建议吗？
MWE 几乎直接摘自上一个答案：
\documentclass{article}
%\url{https://tex.stackexchange.com/q/171931/86}
\usepackage{tikz}
\usepackage{environ}
%we don't actually need externalisation to demonstrate the problem, so turn it off for now
\usetikzlibrary{cd}%,external}
%\tikzexternalize
\usepackage{tabularray}
\makeatletter
\def\tikzcd@[#1]{%
\begin{tikzpicture}[/tikz/commutative diagrams/.cd,every diagram,#1]%
\ifx\arrow\tikzcd@arrow%
\pgfutil@packageerror{tikz-cd}{Diagrams cannot be nested}{}
\fi%
\let\arrow\tikzcd@arrow%
\let\ar\tikzcd@arrow%
\def\rar{\tikzcd@xar{r}}%
\def\lar{\tikzcd@xar{l}}%
\def\dar{\tikzcd@xar{d}}%
\def\uar{\tikzcd@xar{u}}%
\def\urar{\tikzcd@xar{ur}}%
\def\ular{\tikzcd@xar{ul}}%
\def\drar{\tikzcd@xar{dr}}%
\def\dlar{\tikzcd@xar{dl}}%
\global\let\tikzcd@savedpaths\pgfutil@empty%
\matrix[/tikz/matrix of \iftikzcd@mathmode math \fi nodes,
/tikz/every cell/.append code={\tikzcdset{every cell}},
/tikz/commutative diagrams/.cd,every matrix]%
\bgroup}
\def\endtikzcd{%
\pgfmatrixendrow\egroup%
\pgfextra{\global\let\tikzcdmatrixname\tikzlastnode};%
\tikzcdset{\the\pgfmatrixcurrentrow-row diagram/.try}%
\begingroup%
\pgfkeys{% `quotes' library support
/handlers/first char syntax/the character "/.initial=\tikzcd@forward@quotes,%
/tikz/edge quotes mean={%
edge node={node [execute at begin node=\iftikzcd@mathmode$\fi,%$
execute at end node=\iftikzcd@mathmode$\fi,%$
/tikz/commutative diagrams/.cd,every label,##2]{##1}}}}%
\let\tikzcd@errmessage\errmessage% improve error messages
\def\errmessage##1{\tikzcd@errmessage{##1^^J...^^Jl.\tikzcd@lineno\space%
I think the culprit is a tikzcd arrow in cell \tikzcd@currentrow-\tikzcd@currentcolumn}}%
\tikzcd@before@paths@hook%
\tikzcd@savedpaths%
\endgroup%
\end{tikzpicture}%
\ifnum0=`{}\fi}
\NewEnviron{mytikzcd}[1][]{%
\def\@temp{\tikzcd@[#1]\BODY}%
\expandafter\@temp\endtikzcd
}
\makeatother
\def\temp{&} \catcode`&=\active \let&=\temp
\begin{document}
\begin{mytikzcd}
A \arrow{rd} \arrow{r}{\phi} & B \\ & C
\end{mytikzcd}
\begin{mytikzcd}
A \arrow{rd} \arrow{r}{\phi} & B \\ & C
\end{mytikzcd}
%re-add the material below to see the problem that results from global redefinition of the &
% \begin{center}
% \begin{tblr}{
% rows = {35pt}, columns = {35pt},
% rowsep = 1pt, colsep = 1pt, stretch = 0,
% cells = {c,font=\Huge},
% cell{odd}{even} = {azure7},
% cell{even}{odd} = {azure7},
% hlines, vlines,
% }
% a & b & c & d & e & f & g & h \\
% a & b & c & d & e & f & g & h \\
% & & & & & & & \\
% & & & & & & & \\
% & & & & & & & \\
% & & & & & & & \\
% a & b & c & d & e & f & g & h \\
% \end{tblr}
% \end{center}
\end{document}
上下文：这需要在包内操作；我不想告诉用户他们必须在每次使用 mytikzcd 环境之前和之后编写额外的材料。它需要对他们不可见。
答案1
进入前&将catcode 改为，离开后再改回。\activemytikzcd4mytikzcd
\documentclass{article}
%\url{https://tex.stackexchange.com/q/171931/86}
\usepackage{tikz}
\usepackage{environ}
%we don't actually need externalisation to demonstrate the problem, so turn it off for now
\usetikzlibrary{cd}%,external}
%\tikzexternalize
\usepackage{tabularray}
\makeatletter
\def\tikzcd@[#1]{%
\begin{tikzpicture}[/tikz/commutative diagrams/.cd,every diagram,#1]%
\ifx\arrow\tikzcd@arrow%
\pgfutil@packageerror{tikz-cd}{Diagrams cannot be nested}{}
\fi%
\let\arrow\tikzcd@arrow%
\let\ar\tikzcd@arrow%
\def\rar{\tikzcd@xar{r}}%
\def\lar{\tikzcd@xar{l}}%
\def\dar{\tikzcd@xar{d}}%
\def\uar{\tikzcd@xar{u}}%
\def\urar{\tikzcd@xar{ur}}%
\def\ular{\tikzcd@xar{ul}}%
\def\drar{\tikzcd@xar{dr}}%
\def\dlar{\tikzcd@xar{dl}}%
\global\let\tikzcd@savedpaths\pgfutil@empty%
\matrix[/tikz/matrix of \iftikzcd@mathmode math \fi nodes,
/tikz/every cell/.append code={\tikzcdset{every cell}},
/tikz/commutative diagrams/.cd,every matrix]%
\bgroup}
\def\endtikzcd{%
\pgfmatrixendrow\egroup%
\pgfextra{\global\let\tikzcdmatrixname\tikzlastnode};%
\tikzcdset{\the\pgfmatrixcurrentrow-row diagram/.try}%
\begingroup%
\pgfkeys{% `quotes' library support
/handlers/first char syntax/the character "/.initial=\tikzcd@forward@quotes,%
/tikz/edge quotes mean={%
edge node={node [execute at begin node=\iftikzcd@mathmode$\fi,%$
execute at end node=\iftikzcd@mathmode$\fi,%$
/tikz/commutative diagrams/.cd,every label,##2]{##1}}}}%
\let\tikzcd@errmessage\errmessage% improve error messages
\def\errmessage##1{\tikzcd@errmessage{##1^^J...^^Jl.\tikzcd@lineno\space%
I think the culprit is a tikzcd arrow in cell \tikzcd@currentrow-\tikzcd@currentcolumn}}%
\tikzcd@before@paths@hook%
\tikzcd@savedpaths%
\endgroup%
\end{tikzpicture}%
\ifnum0=`{}\fi}
\NewEnviron{mytikzcd}[1][]{%
\def\@temp{\tikzcd@[#1]\BODY}%
\expandafter\@temp\endtikzcd
}
\makeatother
\def\temp{&} \catcode`&=\active \let&=\temp \catcode`&=4
\begin{document}
\catcode`&=\active
\begin{mytikzcd}
A \arrow{rd} \arrow{r}{\phi} & B \\ & C
\end{mytikzcd}
\begin{mytikzcd}
A \arrow{rd} \arrow{r}{\phi} & B \\ & C
\end{mytikzcd}
\catcode`&=4
%re-add the material below to see the problem that results from global redefinition of the &
\begin{center}
\begin{tblr}{
rows = {35pt}, columns = {35pt},
rowsep = 1pt, colsep = 1pt, stretch = 0,
cells = {c,font=\Huge},
cell{odd}{even} = {azure7},
cell{even}{odd} = {azure7},
hlines, vlines,
}
a & b & c & d & e & f & g & h \\
a & b & c & d & e & f & g & h \\
& & & & & & & \\
& & & & & & & \\
& & & & & & & \\
& & & & & & & \\
a & b & c & d & e & f & g & h \\
\end{tblr}
\end{center}
\end{document}
