使用 TikZ-within-TikZ 进行外部化崩溃

Question

在下面的 MWE 中，有一个自定义箭头使用 定义为单独的绘图\tikz。箭头用作边缘节点，以便可以自动倾斜。

我也在使用 TikZexternal包，因为这是包含许多 TikZ 图形的一本书长度的项目的一部分。

梅威瑟：

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{external}
\tikzexternalize

\newcommand{\myarrow}{\tikz{\draw[->] (0,0)--(10pt,0)}}

\begin{document}

    \begin{tikzpicture}

        \node[draw] (1) at (0,0) {};
        \node[draw] (2) at (1,1) {};
            
        \draw (1) to[edge node={node [sloped,above] {\myarrow}}] (2);
        
        \end{tikzpicture}

\end{document}

如果我尝试按原样编译 MWE，我会收到一条错误消息：

/mwe.tex:18: Package tikz Error: Sorry, the system call 'pdflatex -shell-escap
e -halt-on-error -interaction=batchmode -jobname "mwe-figure0" "\def\tikzextern
alrealjob{mwe}\input{mwe}"' did NOT result in a usable output file 'mwe-figure0
' (expected one of .pdf:.jpg:.jpeg:.png:). Please verify that you have enabled 
system calls. For pdflatex, this is 'pdflatex -shell-escape'. Sometimes it is a
lso named 'write 18' or something like that. Or maybe the command simply failed
? Error messages can be found in 'mwe-figure0.log'. If you continue now, I'll t
ry to typeset the picture.

See the tikz package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.18        \end{tikzpicture}
                        
? 
[1{/usr/local/texlive/2021/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
(./mwe.aux) )</usr/local/texlive/2021/texmf-dist/fonts/type1/public/amsfonts/cm
/cmr10.pfb>
Output written on mwe.pdf (1 page, 8538 bytes).
SyncTeX written on mwe.synctex.gz.
Transcript written on mwe.log.

如果我注释掉该\tikzexternalize行，它可以编译成功：

如果我注释掉该\draw (1) ...行，它也能正常编译。有什么建议吗？

Answer 1

因为这不适合注释。已经指出不应嵌套tikzpictures。这也是没有必要的，Ti钾Z 有一个工具可以帮你完成这些工作：pics。这些也可以倾斜，并赋予参数（通过 pgf 键）。

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{external}
\tikzexternalize

\begin{document}

\begin{tikzpicture}[pics/my arrow/.style={code={
    \tikzset{my arrow/.cd,#1}
    \draw[my arrow/arrow] 
    (-\pgfkeysvalueof{/tikz/my arrow/length}/2,\pgfkeysvalueof{/tikz/my arrow/y})
    --(\pgfkeysvalueof{/tikz/my arrow/length}/2,\pgfkeysvalueof{/tikz/my arrow/y});}},
    my arrow/.cd,
    arrow/.style={->},length/.initial=10pt,y/.initial={0pt}]

    \node[draw] (1) at (0,0) {};
    \node[draw] (2) at (1,1) {};

    \draw (1) to pic[sloped]{my arrow={y=4pt}} (2);

\end{tikzpicture}
\end{document}