当节点大小由“最小尺寸”定义时，tikz矩阵分隔符

Question

螺柱 车牌回答问题我发现tikz矩阵定界符的意外行为：如果数学节点的大小由text width=...和确定text height=...，则定界符将按预期工作，但是，如果我用替换它们，minimum size=...则会出现错误!missing } inserted.. <inserted text> }。测试示例：

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{matrix}
\newcommand\x{\times}

\begin{document}
\begin{tikzpicture}
\matrix [matrix of math nodes,
         nodes={rectangle, %draw, very thin,
                minimum size=1.2em, text depth=0.25ex,
                inner sep=0pt, outer sep=0pt,
                left delimiter=(, right delimiter=),
                fill opacity=0.5, text opacity=1,
                anchor=center},
         column sep=-0.5\pgflinewidth,
         row sep=-0.5\pgflinewidth,
         column 2/.append style = {nodes={fill=cyan!50}},
         row 2/.append style = {nodes={fill=cyan!50}},
         row 2 column 2/.append style={nodes={fill=cyan}},
         ]
{
a_1 & \x  & a_3 \\
a_4 & \x  & a_6 \\
a_7 & \x  & a_9 \\
};
\end{tikzpicture}
\end{document}

如果我注释定界符的定义，则示例如下：

我是否遗漏了什么或者做错了什么？

Answer 1

您应该将其放置left delimiter=(, right delimiter=)在nodes选项之外。

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{matrix}
\newcommand\x{\times}

\begin{document}
\begin{tikzpicture}
\matrix [matrix of math nodes,
         nodes={rectangle, %draw, very thin,
                minimum size=1.2em, text depth=0.25ex,
                inner sep=0pt, outer sep=0pt,
                fill opacity=0.5, text opacity=1,
                anchor=center},
         column sep=-0.5\pgflinewidth,
         row sep=-0.5\pgflinewidth,
         column 2/.append style = {nodes={fill=cyan!50}},
         row 2/.append style = {nodes={fill=cyan!50}},
         row 2 column 2/.append style={nodes={fill=cyan}},
         left delimiter={(}, right delimiter={)}
         ]
{
a_1 & \x  & a_3 \\
a_4 & \x  & a_6 \\
a_7 & \x  & a_9 \\
};
\end{tikzpicture}
\end{document}