我重新定义了小节标题，因此目录如下所示：
\documentclass[twoside, a4paper, 12pt, showtrims]{book}
%\usepackage{showframe}
\usepackage[X2,T1,T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{xcolor}
\usepackage[shortlabels]{enumitem}
\usepackage{etoolbox}
\usepackage[pagestyles, newparttoc, explicit]{titlesec}
\usepackage{titletoc}
\usepackage{caption}
\usepackage[linktoc = all]{hyperref}
\usepackage{cleveref}
\usepackage{hypcap}
\usepackage{lipsum}
\renewcommand*\thepart{\Roman{part}}
\renewcommand*\thesection{\S\arabic{section}.}
\renewcommand*\thesubsection{\Roman{subsection}.}
\renewcommand*\thesubsubsection{\arabic{subsubsection}.}
\makeatletter
\renewcommand\subsection{
\@startsection{subsection}{2}{\z@}%
{-3.25ex\@plus -1ex \@minus -.2ex}%
{1.5ex \@plus .2ex}%
{\normalfont\large\bfseries}
%{style}*[toctitle]{title}
%What should be here?
}
\makeatother
\titlecontents*{subsection}
[32 pt]
{\small}
{\thecontentslabel\ }
{}
{\ (\thecontentspage)}
[.\ ]
[]
\begin{document}
\part{The Part}
\chapter{Caption}
\section{Com Primo}
\lipsum[1]
\section{Secondo}
\subsection{Erste}
\subsubsection{SubSub}
This is a test.
\subsection{Subsection 2}
\section{Zweite}
\subsection{Sub 1}
\subsubsection{SubSub 2}
\subsection{Sub Secondo}
\part{The second Part}
\setcounter{tocdepth}{2}
\tableofcontents{}
\end{document}
但是，这种重新定义会破坏指向子节的超链接。此外，我希望在子节也超链接的页面周围使用括号。经过几个小时的搜索，我发现修复它的最佳方法是\section直接更新命令（因为它在中实现book.cls）。
我发现（见这里) 该\@startsection命令（它在 中实现latex.ltx）有六个必需参数。此外，它还有两个额外的参数定义toctitle和title的额外参数，但没有使用。所以我尝试使用它们并手动定义它们。但有一个问题 --- 我想使用小节标题，但我不知道如何访问它。答案成立这里不起作用（我认为是因为titlesec）。
那么，我应该如何重新定义此命令？或者还有其他想法可以实现我想要的功能吗？
编辑1：toc和aux文件：
toc
\babel@toc {english}{}\relax
\contentsline {part}{I\hspace {1em}The Part}{1}{part.1}%
\contentsline {chapter}{\numberline {1}Caption}{3}{chapter.1}%
\contentsline {section}{\numberline {\S 1.}Com Primo}{3}{section.1.1}%
\contentsline {section}{\numberline {\S 2.}Secondo}{3}{section.1.2}%
\contentsline {subsection}{\numberline {I.}Erste}{3}{subsection.1.2.1}%
\contentsline {subsubsection}{SubSub}{3}{subsubsection*.1}%
\contentsline {subsection}{\numberline {II.}Subsection 2}{4}{subsection.1.2.2}%
\contentsline {section}{\numberline {\S 3.}Zweite}{4}{section.1.3}%
\contentsline {subsection}{\numberline {I.}Sub 1}{4}{subsection.1.3.1}%
\contentsline {subsubsection}{SubSub 2}{4}{subsubsection*.2}%
\contentsline {subsection}{\numberline {II.}Sub Secondo}{4}{subsection.1.3.2}%
\contentsline {part}{II\hspace {1em}The second Part}{5}{part.2}%
\contentsfinish
aux
\relax
\providecommand\babel@aux[2]{}
\@nameuse{bbl@beforestart}
\providecommand\hyper@newdestlabel[2]{}
\providecommand\HyperFirstAtBeginDocument{\AtBeginDocument}
\HyperFirstAtBeginDocument{\ifx\hyper@anchor\@undefined
\global\let\oldnewlabel\newlabel
\gdef\newlabel#1#2{\newlabelxx{#1}#2}
\gdef\newlabelxx#1#2#3#4#5#6{\oldnewlabel{#1}{{#2}{#3}}}
\AtEndDocument{\ifx\hyper@anchor\@undefined
\let\newlabel\oldnewlabel
\fi}
\fi}
\global\let\hyper@last\relax
\gdef\HyperFirstAtBeginDocument#1{#1}
\providecommand\HyField@AuxAddToFields[1]{}
\providecommand\HyField@AuxAddToCoFields[2]{}
\babel@aux{english}{}
\@writefile{toc}{\contentsline {part}{I\hspace {1em}The Part}{1}{part.1}\protected@file@percent }
\@writefile{toc}{\contentsline {chapter}{\numberline {1}Caption}{3}{chapter.1}\protected@file@percent }
\@writefile{lof}{\addvspace {10\p@ }}
\@writefile{lot}{\addvspace {10\p@ }}
\@writefile{toc}{\contentsline {section}{\numberline {\S 1.}Com Primo}{3}{section.1.1}\protected@file@percent }
\@writefile{toc}{\contentsline {section}{\numberline {\S 2.}Secondo}{3}{section.1.2}\protected@file@percent }
\@writefile{toc}{\contentsline {subsection}{\numberline {I.}Erste}{3}{subsection.1.2.1}\protected@file@percent }
\@writefile{toc}{\contentsline {subsubsection}{SubSub}{3}{subsubsection*.1}\protected@file@percent }
\@writefile{toc}{\contentsline {subsection}{\numberline {II.}Subsection 2}{4}{subsection.1.2.2}\protected@file@percent }
\@writefile{toc}{\contentsline {section}{\numberline {\S 3.}Zweite}{4}{section.1.3}\protected@file@percent }
\@writefile{toc}{\contentsline {subsection}{\numberline {I.}Sub 1}{4}{subsection.1.3.1}\protected@file@percent }
\@writefile{toc}{\contentsline {subsubsection}{SubSub 2}{4}{subsubsection*.2}\protected@file@percent }
\@writefile{toc}{\contentsline {subsection}{\numberline {II.}Sub Secondo}{4}{subsection.1.3.2}\protected@file@percent }
\@writefile{toc}{\contentsline {part}{II\hspace {1em}The second Part}{5}{part.2}\protected@file@percent }
\ttl@finishall
\gdef \@abspage@last{7}
答案1
\documentclass[twoside, a4paper, 12pt, showtrims]{book}
%\usepackage{showframe}
\usepackage[X2,T1,T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{xcolor}
\usepackage[shortlabels]{enumitem}
\usepackage{etoolbox}
\usepackage[pagestyles, newparttoc, explicit]{titlesec}
\usepackage{titletoc}
\usepackage{caption}
\usepackage[linktoc = all]{hyperref}
\usepackage{cleveref}
\usepackage{hypcap}
\usepackage{lipsum}
\renewcommand*\thepart{\Roman{part}}
\renewcommand*\thesection{\S\arabic{section}.}
\renewcommand*\thesubsection{\Roman{subsection}.}
\renewcommand*\thesubsubsection{\arabic{subsubsection}.}
\makeatletter
\newlength\rightmargintoc
\setlength\rightmargintoc{\linewidth}
\addtolength\rightmargintoc{0em}
\makeatletter
\def\subsectocline#1#2#3#4#5{%
\parshape 2 #2 \rightmargintoc \dimexpr\parindent+3em\relax \rightmargintoc
\@tempdima #3
\ifdim\lastskip=#2\relax\else\fi{{#4}~\hyperlink{\Hy@tocdestname}{(#5)}.}\hskip1em%
}
\renewcommand*\l@subsection{\subsectocline{2}{3em}{3em}}
\makeatother
\pretocmd{\part}{\addtocontents{toc}{\par}}{}{}
\pretocmd{\chapter}{\addtocontents{toc}{\par}}{}{}
\pretocmd{\section}{\addtocontents{toc}{\par}}{}{}
\AtEndDocument{%
\ifnum\value{subsection}>0\relax
\addtocontents{toc}{\par}
\fi}
\begin{document}
\part{The Part}
\chapter{Caption}
\section{Com Primo}
\lipsum[1]
\section{Secondo}
\subsection{Erste}
\subsubsection{SubSub}
This is a test.
\subsection{Subsection 2}
\section{Zweite}
\subsection{Sub 1}
\subsubsection{SubSub 2}
\subsection{Sub Secondo}
\part{The second Part}
\setcounter{tocdepth}{2}
\tableofcontents{}
\end{document}