首先，MWE 及其索引页如下。
\documentclass[12pt]{article}
%%%index setting%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{imakeidx}
\usepackage[colorlinks,linkcolor=blue]{hyperref}
\usepackage[columns=2,columnsep=2em,%rule=0pt,
initsep=1\baselineskip plus 0.2ex minus 0.1ex,%
hangindent=1em,subindent=1em,hangindent=1em,subsubindent=2em]
{idxlayout}%must be after imakeidx
%Index format-----------------------------------------
\usepackage{filecontents}
\begin{filecontents}[overwrite]{\jobname.mst}
headings_flag 1
heading_prefix "{\\bfseries "
heading_suffix "}\\nopagebreak\n"
delim_0 "\\dotfill "
delim_1 "\\dotfill "
delim_2 "\\dotfill "
delim_n "\\idxBdelim"%%change comma before 'see also' for semicolon
\end{filecontents}
\makeindex
%change comma before 'see also' for semicolon---------------
\makeatletter
\def\idxBdelim{\@ifnextchar{\hyperindexformat}{; }{, }}
\def\@commahyperpage#1{\@@commahyperpage#1\idxBdelim{}\idxBdelim{}\\}
\def\@@commahyperpage#1\idxBdelim#2\idxBdelim#3\\{%
\ifx\\#2\\%
\HyInd@pagelink{#1}%
\else
\HyInd@pagelink{#1}\idxBdelim\HyInd@pagelink{#2}%
\fi
}
\makeatother
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
some text\index{red apple} \index{alpple!red \~{}} \index{yellow!apple}\index{alpple!yellow \~{}} \index{green!apple} \index{alpple!green \~{}}with some index entries\index{white pear} \index{pear!white \~{}}
index{yellow!pear} \index{pear!yellow \~{}} \index{green!pear} \index{pear!green \~{}}
\index{yellow!many many many many many many alpple}
\index{alpple!yellow many many many many many many \~{}}
\newpage
and some\index{yellow!pear} \index{pear!yellow \~{}} \index{green!pear} \index{pear!green \~{}}\emph{see also} entries as well.
\index{red apple} \index{alpple!red \~{}} \index{yellow!apple}\index{alpple!yellow \~{}} \index{green!apple} \index{alpple!green \~{}} \index{white pear} \index{pear!white \~{}}
\newpage
\null
\index{alpple!red \~{}|seealso{red apple}}
\index{alpple!yellow \~{}|seealso{yellow apple}}
\index{alpple!yellow many many many many many many \~{}|seealso{yellow many many many many many many apple}}
\index{alpple!green \~{}|seealso{green apple}}
\index{pear!white \~{}|seealso{white pear}}
\index{pear!yellow \~{}|seealso{yellow pear}}
\index{pear!green \~{}|seealso{green pear}}
\printindex
\end{document}
如你所见，索引条目的词条布局很好，除了下面两个 apple 子条目。如果没有“另见”说明但页码很多，问题也存在。
那么有没有办法让这么长的条目输出如下，即每行条目的左右两侧都对齐？顺便说一句，我知道索引条目上的这种对齐问题非常困难，因此，无论是否能解决这个问题，任何努力都是值得欢迎和赞赏的。提前致谢！
答案1
我觉得这是不可能的。相反，我有这个想法让它看起来更好一些。
\documentclass[12pt]{article}
%%%index setting%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{imakeidx}
\usepackage[colorlinks,linkcolor=blue]{hyperref}
\usepackage[columns=2,columnsep=2em,%rule=0pt,
initsep=1\baselineskip plus 0.2ex minus 0.1ex,%
hangindent=1em,subindent=1em,hangindent=1em,subsubindent=2em]
{idxlayout}%must be after imakeidx
%Index format-----------------------------------------
\begin{filecontents}[overwrite]{\jobname.mst}
headings_flag 1
heading_prefix "{\\bfseries "
heading_suffix "}\\nopagebreak\n"
delim_0 "\\dotfill "
delim_1 "\\dotfill "
delim_2 "\\dotfill "
delim_n "\\idxBdelim"%%change comma before 'see also' for semicolon
delim_t ""
\end{filecontents}
\makeindex
%change comma before 'see also' for semicolon---------------
\makeatletter
\def\idxBdelim{\@ifnextchar{\hyperindexformat}{\newline\null\hfill}{, }}
\def\@commahyperpage#1{\@@commahyperpage#1\idxBdelim{}\idxBdelim{}\\}
\def\@@commahyperpage#1\idxBdelim#2\idxBdelim#3\\{%
\ifx\\#2\\%
\HyInd@pagelink{#1}%
\else
\HyInd@pagelink{#1}\idxBdelim\HyInd@pagelink{#2}%
\fi
}
\makeatother
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
some text\index{red apple} \index{alpple!red \~{}} \index{yellow!apple}\index{alpple!yellow \~{}} \index{green!apple} \index{alpple!green \~{}}with some index entries\index{white pear} \index{pear!white \~{}}
index{yellow!pear} \index{pear!yellow \~{}} \index{green!pear} \index{pear!green \~{}}
\index{yellow!many many many many many many alpple}
\index{alpple!yellow many many many many many many \~{}}
\newpage
and some\index{yellow!pear} \index{pear!yellow \~{}} \index{green!pear} \index{pear!green \~{}}\emph{see also} entries as well.
\index{red apple} \index{alpple!red \~{}} \index{yellow!apple}\index{alpple!yellow \~{}} \index{green!apple} \index{alpple!green \~{}} \index{white pear} \index{pear!white \~{}}
\newpage
\null
\index{alpple!red \~{}|seealso{red apple}}
\index{alpple!yellow \~{}|seealso{yellow apple}}
\index{alpple!yellow many many many many many many \~{}|seealso{yellow many many many many many many apple}}
\index{alpple!green \~{}|seealso{green apple}}
\index{pear!white \~{}|seealso{white pear}}
\index{pear!yellow \~{}|seealso{yellow pear}}
\index{pear!green \~{}|seealso{green pear}}
\printindex
\end{document}
