使用 foreach 循环添加节点

Question

我想用foreach循环放置节点，但是下面的代码报错！

\documentclass[border=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
\begin{tikzpicture}
\node (A) {A};
\node [below=1 of A] (B) {B};

\foreach \name/\pos in {C/below=1 of B,D/below=1 of C} {
    \node [\pos] (\name) {\name};
}
\end{tikzpicture}
\end{document}

错误信息：

! Package pgfkeys Error: I do not know the key '/tikz/below=1 of B' and I am go
ing to ignore it. Perhaps you misspelled it.

See the pgfkeys package documentation for explanation.
Type  H <return>  for immediate help.

Answer 1

当谈到哪里需要自己确保扩展，哪里不需要的问题时，我没有在 TikZ 中看到严格的概念。

尝试：

\documentclass[border=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
\begin{tikzpicture}
\node (A) {A};
\node [below=1 of A] (B) {B};

\foreach \name/\pos in {C/below=1 of B,D/below=1 of C} {
    \expanded{\unexpanded{\node}[\pos](\name){\name}};
}
\end{tikzpicture}
\end{document}

Answer 2

虽然它应该按照您建议的方式工作，但我认为最好确保结构并分离变量以获得更灵活的迭代。

结果：

梅威瑟：

\documentclass[border=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
    \begin{tikzpicture}
        \node (A) {A};  
        \foreach \nodename/\pos/\lastnodename/\nodetext in {
            B/below/A/B,
            C/below/B/C,
            D/left/A/left of A,
            E/above/A/above of A,
            G/below left/C/below left of C% <- The percentage symbol is necessary to have that object format per line       
            }
        {
            \node [\pos=1 of \lastnodename] (\nodename) {\nodetext};
        }
    \end{tikzpicture}
\end{document}