自定义列表环境中的换行

Question 1

您可能想要定制\makelabel。

\documentclass{article}

\usepackage{color}
\usepackage{lipsum}

%% \newcommand{\itemColor}[1]{\item[\llap{\textcolor{blue}{#1}\hspace*{.75mm}}]}

\newcommand{\listConfig}{%
  % amount of extra vertical space at top of list:
  \setlength{\topsep}{-10pt}%
  % extra length at top if environment is preceded by a blank line (it
  % should be a rubber length):
  \setlength{\partopsep}{\baselineskip}%
  % amount of vertical space between paragraphs within an item:
  \setlength{\parsep}{\baselineskip}%
  % amount of extra vertical space between items
  \setlength{\itemsep}{-\baselineskip}%
  % horizontal distance between the left margins of the environment
  % and the list; must be nonnegative:
  \setlength{\leftmargin}{2cm}%
  % horizontal distance betwen the right margins of the enviroment and
  % the list; must be nonnegative:
  \setlength{\rightmargin}{0cm}%
  % indentation of first line of an item; can be negative:
  \setlength{\itemindent}{0pt}%
  % separation between end of the box containing the label and the
  % text of the first line of an item:
  \setlength{\labelsep}{2mm}%
}

\newenvironment{descr}{%
  \vspace{.1in}
  \begin{list}{}{%
    \listConfig
% doesn't all of this belong to \listConfig?
    \setlength{\itemsep}{0pt}%
    \setlength{\labelwidth}{2cm}%
    \renewcommand\makelabel[1]{{\color{blue}\smash{\parbox[t]{\dimexpr\labelwidth-.75mm\relax}
                               {\raggedleft\strut##1\strut}}\hfil}}%
    }%
}{\end{list}\vspace{.1in}}

\begin{document}

This is a descriptive environment:

    \begin{descr}
        \item[title 1]\lipsum[1]
        \item[long long long long long long long title]\lipsum[1]
        \item[test]\lipsum[1]
    \end{descr}

\end{document}

Answer

您可能想要定制\makelabel。

\documentclass{article}

\usepackage{color}
\usepackage{lipsum}

%% \newcommand{\itemColor}[1]{\item[\llap{\textcolor{blue}{#1}\hspace*{.75mm}}]}

\newcommand{\listConfig}{%
  % amount of extra vertical space at top of list:
  \setlength{\topsep}{-10pt}%
  % extra length at top if environment is preceded by a blank line (it
  % should be a rubber length):
  \setlength{\partopsep}{\baselineskip}%
  % amount of vertical space between paragraphs within an item:
  \setlength{\parsep}{\baselineskip}%
  % amount of extra vertical space between items
  \setlength{\itemsep}{-\baselineskip}%
  % horizontal distance between the left margins of the environment
  % and the list; must be nonnegative:
  \setlength{\leftmargin}{2cm}%
  % horizontal distance betwen the right margins of the enviroment and
  % the list; must be nonnegative:
  \setlength{\rightmargin}{0cm}%
  % indentation of first line of an item; can be negative:
  \setlength{\itemindent}{0pt}%
  % separation between end of the box containing the label and the
  % text of the first line of an item:
  \setlength{\labelsep}{2mm}%
}

\newenvironment{descr}{%
  \vspace{.1in}
  \begin{list}{}{%
    \listConfig
% doesn't all of this belong to \listConfig?
    \setlength{\itemsep}{0pt}%
    \setlength{\labelwidth}{2cm}%
    \renewcommand\makelabel[1]{{\color{blue}\smash{\parbox[t]{\dimexpr\labelwidth-.75mm\relax}
                               {\raggedleft\strut##1\strut}}\hfil}}%
    }%
}{\end{list}\vspace{.1in}}

\begin{document}

This is a descriptive environment:

    \begin{descr}
        \item[title 1]\lipsum[1]
        \item[long long long long long long long title]\lipsum[1]
        \item[test]\lipsum[1]
    \end{descr}

\end{document}

Question 2

这enumitem包可以做到这一点。此包允许您使用对自定义列表环境（例如description）<key>=<value>。以下键+值几乎可以满足您的要求：（来自文档）

style=multiline：标签放置在一个 parbox 中，其宽度为 leftmargin，必要时可以多行显示。与相同style=standard,align=parleft,labelwidth=!。

唯一的问题是align=parleft导致标签左对齐而不是右对齐。不幸的是enumitem无法识别\parright，但我们可以通过向键\raggedleft中添加来解决这个问题\font=。

我认为这段代码可以实现你想要的功能：

\documentclass{article}

\usepackage{lipsum} %% <- for \lipsum
\usepackage{xcolor}
\usepackage{enumitem}

\begin{document}

%% Note: this \leavevmode is necessary, see the addendum:
\begin{description}[align=parleft,labelwidth=!,
                    font=\raggedleft\normalfont\leavevmode\color{blue},
                    leftmargin=2cm]
\item[title 1] \lipsum[66] %% <- \lipsum[66] is short
\item[long long long long long long long title] \lipsum[66]
\item[test] \lipsum[66]
\end{description}

\end{document}

您可以添加其他键，例如topsep=<...>或itemsep=<...>等，以设置您调整的其他参数。请参阅enumitem文档这里了解更多信息。

替代方案：您也可以parright通过复制的定义parleft并替换\raggedright来定义自己\raggedleft，如下所示：

\SetLabelAlign{parright}{\strut\smash{\parbox[t]\labelwidth{\raggedleft#1}}}

如果您随后使用parright而不是，则可以从键中parleft省略。\raggedleftfont=

如果您打算多次使用此样式，您也可以description通过在前言中添加以下行来一次性更改所有环境。当然，您可以添加我之前提到的其他键。

\setlist[description]{align=parleft,labelwidth=!,font=\raggedleft\normalfont\leavevmode\color{blue},leftmargin=2cm}

如果您想要更频繁地使用这种风格，但又不想重新定义默认描述环境，那么您可以使用以下命令创建自己的环境：

\newlist{mydescr}{description}{1} %% last argument is the maximum depth.
\setlist[mydescr]{align=parleft,labelwidth=!,font=\raggedleft\normalfont\leavevmode\color{blue},leftmargin=2cm}

附录：

我\leavevmode的font=\raggedleft\normalfont\leavevmode\color{blue}是必要的，因为似乎\color不能在“出于技术原因”的开头使用\parbox。我不知道为什么会这样，所以我刚刚问了一个问题关于它，已经已回答。

Answer