是什么原因导致 threeparttable 的标题周围出现多余的垂直空间以及如何删除它？

Question

我刚刚注意到 Donald Arseneau 的出色threeparttable包装在标题前后增加了额外的垂直空间。这可以在下面的 MWE 中看到，我将\abovecaptionskip和设置\belowcaptionskip为零以强调增加的空间。

您能帮我找出增加的垂直空间来自哪里以及如何删除它吗？我试图破译包装代码，但遗憾的是这超出了我的技能水平。

\documentclass[12pt]{article}
\usepackage{threeparttable}
\usepackage{tabularx}
\setlength{\abovecaptionskip}{0pt}
\setlength{\belowcaptionskip}{0pt}
\begin{document}
  \begin{table}[h]
    \caption{Testing testing testing}
    \begin{tabularx}{\linewidth}{XXXX}
      A1 & B1 & C1 & D1 \\
      A2 & B2 & C2 & D2 \\
      A3 & B3 & C3 & D3 \\
    \end{tabularx}
  \end{table}

  \clearpage
  \begin{table}[h]
    % \vskip-\lastskip%\vspace{-.2\baselineskip}
    \begin{threeparttable}
      \caption{Testing testing testing}
      \vskip-\lastskip%\vspace{-.2\baselineskip}
      \begin{tabularx}{\linewidth}{XXXX}
        A1 & B1 & C1 & D1 \\
        A2 & B2 & C2 & D2 \\
        A3 & B3 & C3 & D3 \\
      \end{tabularx}
    \end{threeparttable}
  \end{table}
\end{document}

Answer 1

解决方法是使用以下caption包：

\documentclass[12pt]{article}
\usepackage{tabularx, threeparttable}
\usepackage[skip=0ex]{caption} %you can select desired value

\begin{document}
  \begin{table}[ht]
    \caption{Testing testing testing}
    \begin{tabularx}{\linewidth}{XXXX}
    \hline
      A1 & B1 & C1 & D1 \\
      A2 & B2 & C2 & D2 \\
      A3 & B3 & C3 & D3 \\
    \end{tabularx}
  \end{table}

   \begin{table}[ht]
    \begin{threeparttable}
      \caption{Testing testing testing}
      \begin{tabularx}{\linewidth}{XXXX}
       \hline
        A1 & B1 & C1 & D1 \\
        A2 & B2 & C2 & D2 \\
        A3 & B3 & C3 & D3 \\
      \end{tabularx}
    \end{threeparttable}
  \end{table}
\end{document}

Answer 2

无需附加软件包的修复：将标题放在后面\begin{table}。

它也适用于投影机。（https://tex.stackexchange.com/a/603137/161015）

\documentclass[12pt]{article}
\usepackage{threeparttable}
\usepackage{tabularx}

\begin{document}
    \begin{table}[h]
        \caption{Testing testing testing}
        \begin{tabularx}{\linewidth}{XXXX}
            A1 & B1 & C1 & D1 \\
            A2 & B2 & C2 & D2 \\
            A3 & B3 & C3 & D3 \\
        \end{tabularx}
    \end{table}
    
    \clearpage
    \begin{table}[h]
        \caption{Testing testing testing}% put the caption here <<<
        \begin{threeparttable}  
            \begin{tabularx}{\linewidth}{XXXX}
                A1 & B1 & C1 & D1 \\
                A2 & B2 & C2 & D2 \\
                A3 & B3 & C3 & D3 \\
            \end{tabularx}
        \end{threeparttable}
    \end{table}
\end{document}