tabularx 标题中的文本对齐仅适用于第一列

Question

 \begin{tabularx}{.96\textwidth}{@{\extracolsep{\fill}}|c|c|c| }
 \hline
   \textbf{Xxx1} & 
   \textbf{Xxx2} & 
   \textbf{Xxx3} \\ 
 \hline
   & & \\
 \hline
 \end{tabularx}

为什么 Xxx1 居中（正确）而 Xxx2 和 Xxx3 右对齐（错误）？

Answer 1

\documentclass{article}

\usepackage{tabularx}

\begin{document}
\centering

space is added after the rules;

 \begin{tabular*}{\textwidth}{@{\extracolsep{\fill}}|c|c|c|@{}}
 \hline
   \textbf{Xxx1} & 
   \textbf{Xxx2} & 
   \textbf{Xxx3} \\ 
 \hline
   & & \\
 \hline
 \end{tabular*}

\bigskip
without rules:

\begin{tabular*}{\textwidth}{@{\extracolsep{\fill}}ccc@{}}
 \hline
   \textbf{Xxx1} & 
   \textbf{Xxx2} & 
   \textbf{Xxx3} \\ 
 \hline
   & & \\
 \hline
 \end{tabular*}

\bigskip
not stretched (much more readable)

\begin{tabular}{ccc}
 \hline
   \textbf{Xxx1} & 
   \textbf{Xxx2} & 
   \textbf{Xxx3} \\ 
 \hline
   & & \\
 \hline
 \end{tabular}

\bigskip tabularx

\begin{tabularx}{\textwidth}{@{\extracolsep{\fill}}
|*3{>{\centering\arraybackslash}X|}@{}}
 \hline
   \textbf{Xxx1} & 
   \textbf{Xxx2} & 
   \textbf{Xxx3} \\ 
 \hline
   & & \\
 \hline
 \end{tabularx}

\end{document}