一开始我想要一种方法来指定每个规则的长度\epigraph调用的规则长度。但是在给出建议之后这里，我最终得到了一些代码来计算规则的长度，如下所示：它是文本或作者的长度，以较长者为准。除非文本（或作者...）的长度大于页面宽度的 80%，在这种情况下，规则（和文本/作者）的长度设置为页面长度的 80%。但由于说话很便宜，这里是代码：
\newcommand{\mytextformat}{\itshape\epigraphsize}
\newcommand{\mysourceformat}{\scshape}
\newenvironment{mytext}{\mytextformat}{}
\newenvironment{mysource}{\mysourceformat\hfill}{}
\renewcommand{\textflush}{mytext}
\renewcommand{\sourceflush}{mysource}
\newlength{\epitextlen}
\newlength{\episourcelen}
\newlength{\epilength}
\let\originalepigraph\epigraph
\renewcommand\epigraph[2]%
{%
\setlength{\epitextlen}{\widthof{\mytextformat#1}}%
\setlength{\episourcelen}{\widthof{\mysourceformat#2}}%
\ifdim\epitextlen>\episourcelen%
\setlength{\epilength}{\epitextlen}%
\else%
\setlength{\epilength}{\episourcelen}%
\fi%
\ifdim\epilength>0.8\textwidth%
\setlength{\epilength}{0.8\textwidth}%
\fi%
\setlength{\epigraphwidth}{\epilength}%
\originalepigraph{#1}{#2}%
}
它运行良好，但由于我是 TeX hackery 的新手，我想问是否可以/如何改进它？特别是，当作者的名字比文本大时，一些内容会留在它前面。这不是太严重，但如果有人能告诉我原因，我将不胜感激。提前致谢。
编辑：这是 MWE。@Steven B. Segletes：\mysourceformat按照您的建议更改该行会导致作者行换行成两行。
\documentclass[oneside]{scrbook}
\usepackage{epigraph}
\usepackage{calc}
\newcommand{\mytextformat}{\itshape\epigraphsize}
\newcommand{\mysourceformat}{\scshape}
\newenvironment{mytext}{\mytextformat}{}
\newenvironment{mysource}{\mysourceformat\hfill}{}
\renewcommand{\textflush}{mytext}
\renewcommand{\sourceflush}{mysource}
\newlength{\epitextlen}
\newlength{\episourcelen}
\newlength{\epilength}
\let\originalepigraph\epigraph
\renewcommand\epigraph[2]%
{%
\setlength{\epitextlen}{\widthof{\mytextformat#1}}%
\setlength{\episourcelen}{\widthof{\mysourceformat#2}}%
\ifdim\epitextlen>\episourcelen%
\setlength{\epilength}{\epitextlen}%
\else%
\setlength{\epilength}{\episourcelen}%
\fi%
\ifdim\epilength>0.8\textwidth%
\setlength{\epilength}{0.8\textwidth}%
\fi%
\setlength{\epigraphwidth}{\epilength}%
\originalepigraph{#1}{#2}%
}
\begin{document}
\chapter{Introduction}
\epigraph{IRAV IVQV IVPV}{Gaius Julius C\ae sar} Lorem ipsum.
\end{document}
答案1
为了回答 OP 的直接问题，我提供了此修订。 \epigraphsize必须进入\mysourceformat；我还更新了\renewcommand{\textflush}{flushleft}，和\renewcommand{\sourceflush}{flushright}。最后，需要通过以下方式将所需的格式应用于题词\originalepigraph{\mytextformat#1}{\mysourceformat#2}
：
\documentclass[oneside]{scrbook}
\usepackage{epigraph}
\usepackage{calc}
\newcommand{\mytextformat}{\epigraphsize\itshape}
\newcommand{\mysourceformat}{\epigraphsize\scshape}
\newenvironment{mytext}{\mytextformat}{}
\newenvironment{mysource}{\mysourceformat\hfill}{}
\renewcommand{\textflush}{mytext}
\renewcommand{\sourceflush}{mysource}
\newlength{\epitextlen}
\newlength{\episourcelen}
\newlength{\epilength}
\renewcommand{\textflush}{flushleft}
\renewcommand{\sourceflush}{flushright}
\let\originalepigraph\epigraph
\renewcommand\epigraph[2]%
{%
\setlength{\epitextlen}{\widthof{\mytextformat#1}}%
\setlength{\episourcelen}{\widthof{\mysourceformat#2}}%
\ifdim\epitextlen>\episourcelen%
\setlength{\epilength}{\epitextlen}%
\else%
\setlength{\epilength}{\episourcelen}%
\fi%
\ifdim\epilength>0.8\textwidth%
\setlength{\epilength}{0.8\textwidth}%
\fi%
\setlength{\epigraphwidth}{\epilength}%
\originalepigraph{\mytextformat#1}{\mysourceformat#2}%
}
\begin{document}
\chapter{Introduction}
\epigraph{IRAV IVQV IVPV}{Gaius Julius C\ae sar} Lorem ipsum.
\end{document}
但这里有一个略有不同的方法。它将文本和作者堆叠在一起，并且堆栈宽度将是两者中较大的一个。它使用该堆栈宽度与进行比较.8\linewidth。
行宽的关键在于引用是在 中设置的\epigraphsize。因此，被测试宽度的框也应该在 中设置\epigraphsize。然后，只有在换行时，行才会超出引用或作者，因为换行的文本是不整齐的。（请注意， \textflushOP 引用的答案中的宏会导致文本向右对齐，而不是向左对齐；可以将其注释掉）。
我已编辑答案以允许文本或作者的换行，这将强制线宽达到换行长度。
\documentclass{book}
\usepackage{epigraph}
\usepackage[usestackEOL]{stackengine}
\renewcommand{\epigraphsize}{\small}
\newcommand{\mytextformat}{\epigraphsize\itshape}
\newcommand{\mysourceformat}{\epigraphsize\scshape}
\renewcommand{\textflush}{flushright} \renewcommand{\sourceflush}{flushright}
\let\originalepigraph\epigraph
\renewcommand\epigraph[2]{%
\setbox0=\hbox{\stackon{\textit{\mytextformat\Longstack{#1}}}%
{\mysourceformat\scshape\Longstack{#2}}}%
\ifdim\wd0>.8\linewidth\wd0=.8\linewidth\fi%
\setlength{\epigraphwidth}{\wd0}%
\originalepigraph{\textit{#1}}{\textsc{#2}}%
}
\begin{document}
\epigraph{All models are wrong, but some are useful.}{George E. P. Box}
\epigraph{All models are very wrong, but some are marginally useful.}{George E. P. Box}
Left to autowrap:
\epigraph{All models are very, very, wrong, but some might be marginally useful.}{George E. P. Box}
\epigraph{All models are without a doubt, very, very, wrong, but some might be marginally useful.}{George E. P. Box}
Forcing a linebreak:
\epigraph{All models are very, very, wrong, but some might be marginally\\ useful.}{George E. P. Box}
\epigraph{All models are without a doubt, very, very, wrong, but some might\\ be marginally useful.}{George E. P. Box}
Longer author than quote:
\epigraph{Nuts!}{General Anthony Clement "Nuts" McAuliffe}
\epigraph{Nuts!}{General Anthony Clement "Nuts" McAuliffe (July 2, 1898 -- August 11, 1975), United States Army, acting division commander, 101st Airborne Division, defending Bastogne, Belgium, during World War II's Battle of the Bulge}
\end{document}
