在 booktabs 样式表中未显示垂直线。

Question

我有一张四列的表格，其中有一些注释。我使用booktabs带有垂直线的样式来分隔表格中的两个大类别（硬件和软件）。问题是第一列没有显示垂直线。

可能哪里出了问题？另外，我认为在表格中加垂直线不是一个好主意，但如果没有垂直线，内容就很难阅读；我有什么办法可以删除垂直线，但又能明显地分隔各列。

\documentclass[9pt]{article}

\usepackage{booktabs}
\newcommand{\spaceit}{\hspace{0.2cm}}

\usepackage{threeparttable}

\begin{document}
    \begin{table}[t]
        \caption{Research history \& directions}
        \centering

        \begin{threeparttable}

        \begin{tabular}{@{}l|ll|ll@{}} \toprule
         & \multicolumn{2}{c}{Software} & \multicolumn{2}{c}{Hardware}\\ 
         \cmidrule(r){2-3} \cmidrule(r){4-5}
                     & Data structures \& Algorithms & Software Engineering & Hardware Systems & Communication\\ \midrule
         A & \tnote{1}\spaceit Ray tracing modeling   & Widget framework                 &                                       & VLC\tnote{a} \\ 
         \bottomrule
         \end{tabular}

         \begin{tablenotes}
             \item[1] Published academic research: papers, books, technical reports ({1} -- {10})
             \item[a] Visible Light Communication
             \item[b] Component Based Software Engineering
             \item[c] Data Acquisition System
             \item[d] Web-based System Management
             \item[e] Software \& Hardware Testing System
         \end{tablenotes}

         \end{threeparttable}
    \end{table}         
\end{document}

Answer 1

这是一种更好地区分两组的方法：

\documentclass[9pt]{extarticle}
\usepackage[showframe]{geometry}
\usepackage[table,  svgnames]{xcolor}
\usepackage{booktabs, caption}
\newcommand{\spaceit}{\hspace{0.2cm}}

\usepackage{threeparttable}

\begin{document}

\begin{table}[t]
  \caption{Research history \& directions}
  \centering
  \begin{threeparttable}
    \begin{tabular}{@{}lll cll@{}}
      \arrayrulecolor{black} \cmidrule[\heavyrulewidth]{2-3} \cmidrule[\heavyrulewidth]{5-6}
      & \multicolumn{2}{c}{\bfseries Software} &\raisebox{0pt}[0pt][0pt]{\color{Lavender}\rule[-9.4ex]{1.5em}{12ex}} & \multicolumn{2}{c}{\bfseries Hardware}\\
      \cmidrule(r){2-3} \cmidrule(r){5-6}
        & Data structures \& Algorithms & Software Engineering &   & Hardware Systems & Communication \\
      \addlinespace
      A & \tnote{1}\spaceit Ray tracing modeling & Widget framework & & VLC\tnote{a} \\
      \cmidrule[\heavyrulewidth]{2-3} \cmidrule[\heavyrulewidth]{5-6}
    \end{tabular}
    \smallskip
    \begin{tablenotes}\footnotesize
      \item[1] Published academic research: papers, books, technical reports ({1} -- {10})
      \item[a] Visible Light Communication
      \item[b] Component Based Software Engineering
      \item[c] Data Acquisition System
      \item[d] Web-based System Management
      \item[e] Software \& Hardware Testing System
    \end{tablenotes}
  \end{threeparttable}
\end{table}

\end{document}