在其他路径下定义的样式无法在 \node 中工作

在其他路径下定义的样式无法在 \node 中工作

我编写了以下代码来测试\nodein的使用tikz。我发现使用在另一个路径(本例中为 /a)下定义的样式会导致问题 - 请参阅 MWE 了解详情。有人能帮我找出原因并解决吗?

梅威瑟:

\documentclass[a4paper]{article}
\usepackage{tikz}
\begin{document}

\pgfkeys{/a/.search also={/tikz},
  /a/.cd,
  myshape/.style={fill=red,circle},
  size/.style={minimum size=#1*0.5cm},
  size/.default=1
}

% example No.1:
\tikz\node[fill=red,circle]{AAA}; %The option "circle" can be used dirctly in "\node".

% example No.2:
% Contrasted with example No.1, why can "circle" not be used in myshape/.style which leads to unsuccessful compile?
% \tikz[/tikz/.search also={/a}]\node[myshape]{AAA}; 

% example No.3:
% Why does the "size=3" not work?
\tikz[/tikz/.search also={/a}]\node[fill=red,size=3]{AAA}; 

\end{document}

答案1

你问的是为什么circle有效。这个问题的答案实际上有点微妙,包含在以下代码块中tikz.code.tex

\pgfkeys{/tikz/.unknown/.code=%
  % Is it a pgf key?
  \let\tikz@key\pgfkeyscurrentname%
  \pgfkeys{/pgf/\tikz@key/.try={#1}}%
  \ifpgfkeyssuccess%
  \else%
    \expandafter\pgfutil@in@\expandafter!\expandafter{\tikz@key}%
    \ifpgfutil@in@%
      % this is a color!
      \expandafter\tikz@addoption\expandafter{\expandafter\tikz@compat@color@set\expandafter{\tikz@key}}%
      \edef\tikz@textcolor{\tikz@key}%
    \else%
      \pgfutil@doifcolorelse{\tikz@key}
      {%
        \expandafter\tikz@addoption\expandafter{\expandafter\tikz@compat@color@set\expandafter{\tikz@key}}%
        \edef\tikz@textcolor{\tikz@key}%
      }%
      {%
        % Ok, second chance: This might be an arrow specification:
        \expandafter\pgfutil@in@\expandafter-\expandafter{\tikz@key}%
        \ifpgfutil@in@%
          % Ah, an arrow spec!
          \expandafter\tikz@processarrows\expandafter{\tikz@key}%
        \else%
          % Ok, third chance: A shape!
          \expandafter\ifx\csname pgf@sh@s@\tikz@key\endcsname\relax%
            \pgfkeys{/errors/unknown key/.expand
              once=\expandafter{\expandafter/\expandafter t\expandafter i\expandafter k\expandafter z\expandafter/\tikz@key}{#1}}%
          \else%
            \edef\tikz@shape{\tikz@key}%
          \fi%
        \fi%
      }%
    \fi%
  \fi%
}%

正如你所见,TiZ 尝试了各种各样的方法。这对用户来说很方便,因为他们可以说circle而不是shape=circlered而不是color=red

你可以让你的代码与 一起工作/.try。但是,我不建议这样做。相反,我建议只给 TiZ 缺失的信息,即说shape=circle而不是circle/pgf/minimum size而不是minimum size

\documentclass[a4paper]{article}
\usepackage{tikz}
\begin{document}

\pgfkeys{/a/.search also={/tikz},
  /a/.cd,
  myshape/.style={fill=red,shape=circle},
  size/.style={/pgf/minimum size=#1*0.5cm},
  size/.default=1
}

% example No.1:
\tikz\node[fill=red,circle]{AAA}; %The option "circle" can be used dirctly in "\node".

% example No.2:
% Contrasted with example No.1, why can "circle" not be used in myshape/.style which leads to unsuccessful compile?
\tikz[/tikz/.search also={/a}]\node[myshape]{AAA}; 

% example No.3:
% Why does the "size=3" not work?
\tikz[/tikz/.search also={/a}]\node[fill=red,size=3]{AAA}; 

\end{document}

我推荐这个的原因在于如果你过度使用/.try诸如此类的东西,哪个键具有优先权就会变得越来越不清楚。

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