是否可以将横向长表的第一部分与页面内边距对齐？当我将书旋转 90 度阅读表格时，我希望表格位于页面对的中心。
\documentclass{memoir}
\pagestyle{showlocs}
\usepackage{booktabs}
\usepackage{longtable}
\usepackage[referable]{threeparttablex}
\usepackage{blindtext}
\usepackage{lscape}
\usepackage{afterpage}
\begin{document}
\mainmatter
\chapter{A chapter}
\Blindtext[3]
\section{A section}
\Blindtext[7]
\afterpage{\begin{landscape}
\begin{ThreePartTable}
\begin{TableNotes}
\item[a] \label{tn:a} Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
\item[b] \label{tn:b} Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
\source Made up
\end{TableNotes}
\begin{longtable}{l l l}
\caption{A long table}\\
\toprule
Column 1 & Column 2 & Column 3 \\
\midrule
\endfirsthead
\bottomrule
\insertTableNotes\\
\endlastfoot
First line\tnotex{tn:a} & 123 & 456 \\
Second line\tnotex{tn:b} & 123 & 456 \\
Third line & 123 & 456 \\
Fourth line & 123 & 456 \\
Fifth line & 123 & 456 \\
Sixth line & 123 & 456 \\
Seventh line & 123 & 456 \\
Eighth line & 123 & 456 \\
Nineth line & 123 & 456 \\
Tenth line & 123 & 456 \\
Eleventh line & 123 & 456 \\
Twelfth line & 123 & 456 \\
Thirteenth line & 123 & 456 \\
Fourteenth line & 123 & 456 \\
Fifteenth line & 123 & 456 \\
Sixteenth line & 123 & 456 \\
Seventeenth line & 123 & 456 \\
\newpage
Eighteenth line & 123 & 456 \\
Nineteenth line & 123 & 456 \\
Twentieth line & 123 & 456 \\
\end{longtable}
\end{ThreePartTable}
\end{landscape}}
\Blindtext[5]
\end{document}