限制节点大小的变化 Tikz

Question

如何限制幻灯片 2 上节点大小的变化？我相信这是由于下标引起的，但不知道如何解决。

\documentclass{beamer}
\usepackage{tikz}
\usepackage{calc}
\usepackage{fixltx2e}
\usetikzlibrary{positioning,calc}
\begin{document}

\newlength{\zerooffset}
\begin{frame}
  \begin{tikzpicture}[overlay,remember picture]
    \node[draw,minimum size=1.2cm,rectangle] at (current page.center) (s1) {p};

    \onslide<1>{
      \setlength{\zerooffset}{\widthof{Z\textsubscript{0}}}
      \node[draw,below=1.6cm of s1,anchor=south west,text height=1cm,align=left,text width=1cm,
      xshift={\dimexpr-0.5\zerooffset-\pgfkeysvalueof{/pgf/inner xsep}}] (s3) {Z\textsubscript{0}};
      \draw[->,thick] let \p1=(s1.south),\p2=(s3.north) in (\x1,\y1)--(\x1,\y2);
    }

    \onslide<2>{
      \setlength{\zerooffset}{\widthof{X}}
      \node[draw,below=1.6cm of s1,anchor=south west,text height=1cm,text width=1cm,
      xshift={\dimexpr-0.5\zerooffset-\pgfkeysvalueof{/pgf/inner xsep}}] (s3) {X};

      \draw[->,thick] let \p1=(s1.south),\p2=(s3.north) in (\x1,\y1)--(\x1,\y2);
    }

  \end{tikzpicture}
\end{frame}
\end{document}

Answer 1

在第二个节点（节点“p”下方）的定义中，text depth=0.25cm在其节点内容中添加或\vphantom{Z\textsubscript{0}}。

由于您的代码对我来说不清楚，我只能建议一些小小的改进：

\documentclass{beamer}
\usepackage{tikz}
\usepackage{calc}
\usepackage{fixltx2e}
\usetikzlibrary{positioning,calc}
\begin{document}

\newlength{\zerooffset}
\begin{frame}
  \begin{tikzpicture}[overlay,remember picture,
second node/.style = {%
    draw,
    text height=1cm, text depth=0.25mm, text width=1cm,
    align=left, anchor=south west}
                    ]
    \node[draw,minimum size=1.2cm] at (current page.center) (s1) {p};

    \onslide<1>{
      \setlength{\zerooffset}{\widthof{Z\textsubscript{0}}}
      \node[second node,below=1.6cm of s1,
      xshift={\dimexpr-0.5\zerooffset-\pgfkeysvalueof{/pgf/inner xsep}}] (s3) {Z\textsubscript{0}};
      \draw[->,thick] let \p1=(s1.south),\p2=(s3.north) in (\x1,\y1)--(\x1,\y2);
    }

    \onslide<2>{
      \setlength{\zerooffset}{\widthof{X}}
      \node[second node,below=1.6cm of s1,
      xshift={\dimexpr-0.5\zerooffset-\pgfkeysvalueof{/pgf/inner xsep}}] (s3) {X};    
      \draw[->,thick] let \p1=(s1.south),\p2=(s3.north) in (\x1,\y1)--(\x1,\y2);
    }    
  \end{tikzpicture}
\end{frame}
\end{document}