我有以下侧向表格，其中标题和最后一个单元格需要跨越两列并带有换行符，否则表格将无法阅读。“specs”列只是在“主题”行中是必需的，而不是在标题和有问题的行中。
我的问题出在“标题 4”以及有问题的行中的单元格。
\begin{sidewaystable}
\sffamily
\centering
\setlength\extrarowheight{4pt}
\begin{tabularx}{\textwidth}{@{}>{\bfseries}l|XrXrXrXr|}
& \multicolumn{2}{l}{{Header 1}} & \multicolumn{2}{l}{{Header 2}} & \multicolumn{2}{l}{{Header 3}} & \multicolumn{2}{X}{{Header 4, which is too long}}\\ \hline
Topic 1 &$P_{1a}$.& Spec. &$P_{2a}$.& Spec. & $P_{3a}$.& Spec. &$P_{4a}$ &Spec.\\
More topics &...&...&...&...&...&...&...&...\\
Problematic line:&
\multicolumn{2}{X}{Long text over two columns, which necessitates a line break}&
\multicolumn{2}{X}{Long text over two columns, which necessitates a line break}&
\multicolumn{2}{X}{Long text over two columns, which necessitates a line break}&
\multicolumn{2}{X}{Long text over two columns, which necessitates a line break}\\
\end{tabularx}
\end{sidewaystable}
如果我在多列规范中不使用“X”，而是使用“l”，则换行符不起作用，但单元格会覆盖两列。
在这种情况下，如何才能同时出现换行符和多列单元格？
答案1
类似于@Bernard 的回答（+1），但没有\makebox[\linewidth]{...}并使用makecell包来编写列标题并在单元格内容周围添加更多垂直空间：
\documentclass{article}
\usepackage{rotating}
\usepackage{ragged2e}
\usepackage{makecell, tabularx}
\renewcommand\theadfont{\normalsize}
\renewcommand\theadgape{}
\setcellgapes{3pt}
\begin{document}
\begin{sidewaystable}
\sffamily
\centering
\makegapedcells
\begin{tabularx}{\textwidth}{@{}>{\bfseries}l|*{4}{>{\RaggedRight\arraybackslash}X}|}
& \thead[b]{Header 1}
& \thead[b]{Header 2}
& \thead[b]{Header 3}
& \thead[b]{Header 4, which is\\
longer than one line} \\ \hline
Topic 1 &$P_{1a}$.\hfill Spec.
& $P_{2a}$. \hfill Spec.
& $P_{3a}$.\hfill Spec.
& $P_{4a}$ \hfill Spec. \\
More topics
& \dots\hfill\dots
& \dots\hfill\dots
& \dots\hfill\dots
& \dots\hfill\dots \\
Problematic line:
& A long text over many rows, which necessitates a line break
& A long text over many rows, which necessitates a line break
& A long text over many rows, which necessitates a line break
& A long text over many rows, which necessitates a line break
\end{tabularx}
\end{sidewaystable}
\end{document}
附录： 不幸的是你没有提供必要的信息，今天我的水晶球也坏了……根据你的评论，我估计，我的答案的以下变体（稍微修复了你的姆韦）应该做你想做的事：
\documentclass{article}
\usepackage{rotating}
\usepackage{ragged2e}
\usepackage{makecell, tabularx}
\renewcommand\theadfont{\normalsize}
\renewcommand\theadgape{}
\setcellgapes{3pt}
\newcolumntype{L}{>{\RaggedRight\arraybackslash}X}
\newcolumntype{R}{>{\RaggedLeft\arraybackslash}X}
\begin{document}
\begin{sidewaystable}
\sffamily
\centering
\makegapedcells
\newcommand\mcxx[1]{\multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep}L}{#1}}
\newcommand\mcxl[1]{\multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep}L|}{#1}}
\begin{tabularx}{\textwidth}{@{}>{\bfseries}l|*{4}{L R}|}
& \mcxx{\thead[b]{Header 1}}
& \mcxx{\thead[b]{Header 2}}
& \mcxx{\thead[b]{Header 3}}
& \mcxl{\thead[b]{Header 4, which is\\
longer than one line}} \\ \hline
Topic 1 &$P_{1a}$. and some more text
& Spec.
& $P_{2a}$. & Spec.
& $P_{3a}$. & Spec.
& $P_{4a}$. & Spec. \\
More topics
& \dots & \dots
& \dots & \dots
& \dots & \dots
& \dots & \dots \\
Problematic line:
& \mcxx{A long text over many rows, which necessitates a line break}
& \mcxx{A long text over many rows, which necessitates a line break}
& \mcxx{A long text over many rows, which necessitates a line break}
& \mcxl{A long text over many rows, which necessitates a line break}
\end{tabularx}
\end{sidewaystable}
\end{document}
答案2
这个布局怎么样？
\documentclass{article}
\usepackage{rotating}
\usepackage{tabularx}
\usepackage{ragged2e}
\begin{document}
\begin{sidewaystable}
\sffamily \setlength{\tabcolsep}{4pt}
\centering
\setlength\extrarowheight{4pt}
\begin{tabularx}{\textwidth}{@{}>{\bfseries}l|*{4}{>{\RaggedRight\arraybackslash}X}|}
& Header 1 & Header 2 & Header 3 & Header 4, which is too long \\ \hline
Topic 1 & {\begin{tabularx}{\linewidth}{@{}Xr@{}} $P_{1a}$. & Spec.\end{tabularx}} & {\begin{tabularx}{\linewidth}{@{}Xr@{}} $P_{2a}$. & Spec.\end{tabularx}} & {\begin{tabularx}{\linewidth}{@{}Xr@{}} $P_{3a}$. & Spec.\end{tabularx}} & {\begin{tabularx}{\linewidth}{@{}Xr@{}} $P_{4a}$. & Spec.\end{tabularx}} \\
More topics & \makebox[\linewidth]{ ... \hfill ...} & \makebox[\linewidth]{ ... \hfill ...} & \makebox[\linewidth]{ ... \hfill ...} & \makebox[\linewidth]{ ... \hfill ...} \\
Problematic line:&
A long text over two co\-lumns, which necessitates a line break &
A long text over two co\-lumns, which necessitates a line break &
A long text over two co\-lumns, which necessitates a line break &
A long text over two co\-lumns, which necessitates a line break
\end{tabularx}
\end{sidewaystable}
\end{document}
答案3
借助它可以调整类型列>{\hsize=.75\hsize}的宽度：X
\documentclass{article}
\usepackage{rotating}
\usepackage{tabularx}
\usepackage{ragged2e}
\begin{document}
\begin{sidewaystable}
\sffamily
\centering
\setlength\extrarowheight{4pt}
\begin{tabularx}{\textwidth}{@{}>{\bfseries}l|*{4}{>{\hsize=.75\hsize}X>{\hsize=.25\hsize\RaggedLeft}X}|}
& \multicolumn{2}{l}{{Header 1}} & \multicolumn{2}{l}{{Header 2}} & \multicolumn{2}{l}{{Header 3}} & \multicolumn{2}{X}{{Header 4, which is too long}}\\ \hline
Topic 1 &$P_{1a}$.& Spec. &$P_{2a}$.& Spec. & $P_{3a}$.& Spec. &$P_{4a}$ &Spec.\\
More topics &...&...&...&...&...&...&...&...\\
Problematic line:&
\multicolumn{2}{>{\RaggedRight}X}{Long text over two columns, which necessitates a line break}&
\multicolumn{2}{>{\RaggedRight}X}{Long text over two columns, which necessitates a line break}&
\multicolumn{2}{>{\RaggedRight}X}{Long text over two columns, which necessitates a line break}&
\multicolumn{2}{>{\RaggedRight}X}{Long text over two columns, which necessitates a line break}\\
\end{tabularx}
\end{sidewaystable}
\end{document}