将标题保存在框中

Question

我想通过排版来测量标题的高度\savebox，但遇到

除领导者外，您不能在这里使用'\hrule'。

下面的 MWE 中的有问题的行已被注释掉。

代码

\documentclass{article}
\usepackage{caption}
\usepackage{graphicx}

\newsavebox{\CaptionSavebox}
\captionsetup{width=0.20\linewidth}%

\newcommand*{\CaptionText}{This is a caption for the above figure}

\begin{document}
\begin{figure}
    %\savebox{\CaptionSavebox}{\captionof{figure}{\CaptionText}}% <--- Why can't I do this?
    \centering
    \includegraphics[width=.25\linewidth]{example-image-a}
    \usebox{\CaptionSavebox}%
    \captionof{figure}{\CaptionText}% <-- don't need this if have the caption in the savebox
    \label{fig: figure label}%
\end{figure}%
\end{document}

Answer 1

我猜是因为\savebox将内容放在 中，\hbox所以问题在于标题可能不止一行。你可以将其放在 中来解决这个问题\parbox。

框中的标题下方多了一个空行。这似乎是为了\caption确保它位于自己的一行而产生的。下面我删除了那行。

\documentclass{article}
\usepackage{lipsum}
\usepackage{caption}
\usepackage{graphicx}

\newsavebox{\CaptionSavebox}
\captionsetup{width=0.20\linewidth}%

\newcommand*{\CaptionText}{This is a caption for the above figure}
\begin{document}
\lipsum[1]

\begin{figure}[htb]
    %\savebox{\CaptionSavebox}{\captionof{figure}{\CaptionText}}% <--- Why can't I do this?
    \centering
    \includegraphics[width=.25\linewidth]{example-image-a}
    %%
    \savebox{\CaptionSavebox}{\parbox[b]{\captionwidth}{\caption{\CaptionText}\vspace{-\baselineskip}}}
    \par
    \usebox{\CaptionSavebox}%
    \rlap{\rule{0.5pt}{\ht\CaptionSavebox} Height=\the\ht\CaptionSavebox Depth=\the\dp\CaptionSavebox}
    %%\captionof{figure}{\CaptionText}% <-- don't need this if have the caption in the savebox
    \label{fig: figure label}%
\end{figure}%

\lipsum[2]
\end{document}