将多行部分标题置于目录中

Question

我被难住了。如何让多行部分标题在目录中居中？

\documentclass[a4paper,12pt,openright]{book}  

\usepackage{tocloft}% toc spacing and ragged right (below)  
\cftpagenumbersoff{part}  
\renewcommand{\cfttoctitlefont}{\hfill\Large}  
\renewcommand{\cftaftertoctitle}{\hfill}  

\begin{document}

\tableofcontents  
\chapter{Chapter 1}  
\chapter{Chapter 2}  
\part{A moderately long part title}  
\chapter{Chapter 3}  
\chapter{Chapter 4}  
\chapter{Chapter 5}  
\part{A Very very very long part title which runs over multiple lines in the table of contents}  
\chapter{Chapter 6}  
\chapter{Chapter 7}  
\chapter{Chapter 8}  

\end{document}

理想情况下，我希望目录的布局如下：

                       Contents             

1. 引言.................................................................................................................................................................................................1

                       Part I
            A moderately long part title
   

2. 第 2 章 ...................................................................................................................................................................................... 10

3. 第 3 章 ...................................................................................................................................................................................... 20

4. 第 4 章 ...................................................................................................................................................................................... 30

                      Part II
    A Very very very long part title which runs 
    over multiple lines in the table of contents
   

5. 第 5 章 ...................................................................................................................................................................................... 40

6. 第 6 章 ...................................................................................................................................................................................... 50

如果之前已经问过这个问题，我很抱歉，但我已经花了几个小时尝试寻找解决方案，但无济于事。

Answer 1

在我看来，使用补丁\@part比使用命令更容易tocloft。

\documentclass[a4paper,12pt,openright]{book}  

\usepackage{xpatch}
\usepackage{tocloft}% toc spacing and ragged right (below)  



%\cftpagenumbersoff{part}  
\makeatletter
\xpatchcmd{\@part}{%
  \addcontentsline{toc}{part}{\thepart\hspace{1em}#1}%
}{%
  % Rather use an `\addcontentsline` to get rid off the restrictions of `\contentsline` etc. 
  \addtocontents{toc}{\begingroup\Large \mdseries\protect\centering\partname\ \thepart\par\large\protect\centering#1\par\endgroup}
}{}{}


\makeatother

\renewcommand{\cfttoctitlefont}{\hfill\Large}  
\renewcommand{\cftaftertoctitle}{\hfill}  


\begin{document}

\tableofcontents  
\chapter{Chapter 1}  
\chapter{Chapter 2}  
\part{A moderately long part title}  
\chapter{Chapter 3}  
\chapter{Chapter 4}  
\chapter{Chapter 5}  
\part{A Very very very long part title which runs over multiple lines in the table of contents}  
\chapter{Chapter 6}  
\chapter{Chapter 7}  
\chapter{Chapter 8}  

\end{document}

不同的设置\parbox

\documentclass[a4paper,12pt,openright]{book}  




\usepackage{xpatch}
\usepackage{tocloft}% toc spacing and ragged right (below)  


\DeclareRobustCommand{\wrapmytitles}[1]{%
  \leavevmode

  \centering
  \parbox{0.7\linewidth}{\centering #1}%

}

\makeatletter
\xpatchcmd{\@part}{%
  \addcontentsline{toc}{part}{\thepart\hspace{1em}#1}%
}{%
  \addtocontents{toc}{\begingroup\Large \mdseries\protect\centering\partname\ \thepart\par\large\wrapmytitles{#1}\endgroup}
}{}{}


\makeatother

\renewcommand{\cfttoctitlefont}{\hfill\Large}  
\renewcommand{\cftaftertoctitle}{\hfill}  


\begin{document}

\tableofcontents  
\chapter{Chapter 1}  
\chapter{Chapter 2}  
\part{A moderately long part title}  
\chapter{Chapter 3}  
\chapter{Chapter 4}  
\chapter{Chapter 5}  
\part{A Very very very long part title which runs over multiple lines in the table of contents}  
\chapter{Chapter 6}  
\chapter{Chapter 7}  
\chapter{Chapter 8}  

\end{document}