与颜色框水平对齐

Question

我对将三部分表格居中感到很沮丧

\documentclass{article}
\usepackage[flushleft]{threeparttable}
\usepackage{booktabs,xcolor,siunitx}
\definecolor{lightgray}{gray}{0.9}
\begin{document}

\begin{table}[!ht]
\caption[Table]{Text\tnote{a}.}\label{table1}
\begin{threeparttable}
    \begingroup\setlength{\fboxsep}{0pt}
    \colorbox{lightgray}{% for grey shade
        \begin{tabular}{l l l}
            \hline \hline
            \vspace{-0,2cm}&&\\
            \textbf{1st Column} & \textbf{2nd Column} & \textbf{3rd Column} \\ \midrule
            test\tnote{\textdagger}   &                     &                      \\
            \bottomrule
        \end{tabular}
    }\endgroup % for grey shade
    \begin{tablenotes}
        \item[\textdagger] test
    \end{tablenotes}
\end{threeparttable}    
\end{table}

\end{document}

我尝试过几次将其置于 center-environment 中，也尝试过几次 \centering，但都不起作用。显然，问题出在

\begingroup\setlength{\fboxsep}{0pt}

有人有解决方案吗？我将不胜感激任何帮助。

该表如下所示：

Answer 1

这是一个解决方法：

\documentclass{article}
\usepackage[showframe]{geometry}
\usepackage[flushleft]{threeparttablex}%
\usepackage{booktabs,longtable, caption, cellspace, hhline}
\usepackage{siunitx}
\usepackage[table]{xcolor}
\definecolor{lightgray}{gray}{0.9}

\begin{document}

\begin{table}[!ht]
\centering\captionsetup{skip = 4pt}
\setlength{\aboverulesep}{0pt}
\setlength{\belowrulesep}{0pt}
\setlength{\cellspacetoplimit}{5pt}
\setlength{\cellspacebottomlimit}{5pt}
\begin{threeparttable}
\caption[Table]{Text\tnote{a}.}\label{table1}
\rowcolors{1}{lightgray}{lightgray}
 \begin{tabular}{Cl l l}
            \toprule\arrayrulecolor{lightgray}\midrule[0.5ex]\arrayrulecolor{black} \midrule
            \textbf{1st Column} & \textbf{2nd Column} & \textbf{3rd Column} \\ \midrule
            test\tnote{\textdagger} & & \\
            \bottomrule
        \end{tabular}
    \begin{tablenotes}
        \item[\textdagger] test
    \end{tablenotes}
\end{threeparttable}
\end{table}

\end{document} 

Answer 2

这是一个解决方法；colorbox在里面放一个额外的tabular。

\documentclass{article}
\usepackage[flushleft]{threeparttable}
\usepackage{booktabs,xcolor,siunitx}
\definecolor{lightgray}{gray}{0.9}
\begin{document}

\begin{table}[!ht]\centering
\caption[Table]{Text\tnote{a}.}\label{table1}
\begin{threeparttable}\begin{tabular}{@{}c@{}}%
    \begingroup\setlength{\fboxsep}{0pt}%    <-----
    \colorbox{lightgray}{% for grey shade
        \begin{tabular}{l l l}
            \hline \hline
            \vspace{-0,2cm}&&\\
            \textbf{1st Column} & \textbf{2nd Column} & \textbf{3rd Column} \\ \midrule
            test\tnote{\textdagger}   &                     &                      \\
            \bottomrule
        \end{tabular}%
    }\endgroup % for grey shade
    \end{tabular}                       %    <-----
    \begin{tablenotes}
        \item[\textdagger] test
    \end{tablenotes}
\end{threeparttable}    
\end{table}

\end{document}

Answer 3

这是另一种解决方法，使用parbox封闭tablenotes环境。

\documentclass{article}
\usepackage{threeparttable}
\usepackage{booktabs,xcolor,siunitx}
\definecolor{lightgray}{gray}{0.9}
\begin{document}

\begin{table}[!ht]
\centering
\caption[Table]{Text\tnote{a}.}\label{table1}
\begin{threeparttable}
    \begingroup\setlength{\fboxsep}{0pt}
    \colorbox{lightgray}{% for grey shade
        \begin{tabular}{l l l}
            \hline \hline
            \vspace{-0,2cm}&&\\
            \textbf{1st Column} & \textbf{2nd Column} & \textbf{3rd Column} \\ \midrule
            test\tnote{\textdagger}   &                     &                      \\
            \bottomrule
        \end{tabular}
    }\endgroup % for grey shade

    \parbox{\linewidth}{
    \begin{tablenotes}[flushleft]
     \item[\textdagger] test
    \end{tablenotes}}
\end{threeparttable}    
\end{table}

\end{document}