我试图定义一个新的环境，其中所有段落都应采用新的缩进。我尝试使用\hangafter和\hangindent来执行此操作。但是，这些命令仅适用于其后的第一个段落。如下例所示：
\documentclass{book}
\usepackage{indentfirst} %make first para after title indented
\setlength{\parindent}{2em}
\newenvironment{poemcontent}{\hangafter=1 \setlength{\hangindent}{4em}}{\par}
\newcommand{\text}{This is some content to be written as a single paragraph.
This is some content to be written as a single paragraph. This is some content
to be written as a single paragraph. This is some content to be written as a
single paragraph.}
\begin{document}
\chapter{Poem}
\begin{poemcontent}
\text
\text
\text
\end{poemcontent}
\end{document}
结果是：
我怎么解决这个问题？
答案1
使用以下命令的简单解决方案 everypar：
\documentclass{book}
\usepackage{indentfirst} %make first para after title indented
\setlength{\parindent}{2em}
\newenvironment{poemcontent}{\everypar{\hangafter=1 \setlength{\hangindent}{4em}}}{\par}
\newcommand{\text}{This is some content to be written as a single paragraph.
This is some content to be written as a single paragraph. This is some content
to be written as a single paragraph. This is some content to be written as a
single paragraph.}
\begin{document}
\chapter{Poem}
\begin{poemcontent}
\text
\text
\text
\end{poemcontent}
\end{document}
答案2
传播段落形状正是乳胶列表环境的设计目的。
\documentclass{book}
\usepackage{indentfirst,enumitem} %make first para after title indented
\setlength{\parindent}{2em}
\newlist{plist}{description}{1}
\newenvironment{poemcontent}{%
\plist}{%
\endplist}
\newcommand{\text}{\item This is some content to be written as a single paragraph.
This is some content to be written as a single paragraph. This is some content
to be written as a single paragraph. This is some content to be written as a
single paragraph.}
\begin{document}
\chapter{Poem}
\begin{poemcontent}
\text
\text
\text
\end{poemcontent}
\end{document}
正如您所看到的，我只是在这里采用了默认值，这可能没问题，或者摆弄选项enumitem以进一步定制它。
或者您可能更喜欢这种形式，它只使用一个隐藏\item[]并且只使用空白行\par来触发悬挂缩进：
\documentclass{book}
\usepackage{indentfirst,enumitem} %make first para after title indented
\setlength{\parindent}{2em}
\newlist{plist}{description}{1}
\newenvironment{poemcontent}{%
\plist[listparindent=-2em]\item\relax}{%
\endplist}
\newcommand{\text}{This is some content to be written as a single paragraph.
This is some content to be written as a single paragraph. This is some content
to be written as a single paragraph. This is some content to be written as a
single paragraph.}
\begin{document}
\chapter{Poem}
\begin{poemcontent}
\text
\text
\text
\end{poemcontent}
\end{document}
答案3
如果您确实要排版诗歌，我强烈建议您查看一些已经支持此功能的软件包。（为什么要重新发明轮子？）
例如，诗允许您执行这样的操作，并且非常易于配置：
\documentclass{book}
\usepackage{indentfirst} %make first para after title indented
\usepackage{verse}
\setlength\vindent{4em}
\newcommand{\text}{This is some content to be written as a single paragraph.
This is some content to be written as a single paragraph. This is some content
to be written as a single paragraph. This is some content to be written as a
single paragraph.}
\begin{document}
\poemtitle{Poem}
\begin{verse}[\textwidth]
\text\\
\text\\
\text\\
\end{verse}
\end{document}
如果你正在排版一本诗集，请参阅诗歌文本这是为此设计的（并且可以与诗， 我认为）。
也许，悬挂很有趣。
答案4
尝试xgalley的“多段落\parshape设置”：
\documentclass{article}
\usepackage{xgalley}
% http://river-valley.zeeba.tv/media/conferences/tug-2015/0302-Joseph-Wright/
\ExplSyntaxOn
\cs_new_eq:NN \SetAllShape \galley_parshape_set_multi:nnnN % Normal, left, right, resume
\cs_new_eq:NN \SetOneShape \galley_parshape_set_single:nnnN % Normal, left, right, resume
\cs_new_eq:NN \True \c_true_bool
\cs_new_eq:NN \False \c_false_bool
\ExplSyntaxOff
\newenvironment{poemcontent}[1][4em]
{\par\setlength{\parindent}{0pt}% Remove regular paragraph indentation
\SetAllShape{1}{#1}{0pt}{\False}}
{\par}
\newcommand{\text}{This is some content to be written as a single paragraph.
This is some content to be written as a single paragraph. This is some content
to be written as a single paragraph. This is some content to be written as a
single paragraph.}
\begin{document}
\text
\begin{poemcontent}
\text
\text
\end{poemcontent}
\text
\begin{poemcontent}[3em]
\text
\end{poemcontent}
\text
\end{document}
\SetAllShape{<normal>}{<left>}{<right>}{<resume>}将定义范围内的所有段落设置为前几<normal>行不受影响/正常，后跟按长度 / 向左/向右缩进的段落形状<left>。<right>这可以是逗号分隔的长度列表。<resume>是\True或\False取决于您是否希望缩进停止或继续。