Is it possible to use an \hdashrule inside a \ctable as a \midrule?

Question

I would like to know if there is a way to use an \hdashrule or \hdashline inside a \ctableas a \midrule? If possible, it will obey to the same rules as the \midrule command, like adjusting automatically to the table width and conserving the vertical spacing between the rows.

I tried the following table :

\documentclass[11pt]{book}
\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}
\usepackage{multicol,bm}
\usepackage{array, booktabs}
\usepackage{ctable, dashrule}
\usepackage[left=2cm, right=2cm, top=2cm, bottom=2cm]{geometry}

\begin{document}
\ctable[caption= {Paramètres},
        label  = {tab:paramètres},
        ]
        {m{6.cm} m{3.5cm} l }
        {\tnote[$\ast$]{Dans le repère du solide.} \tnote[$\ast \ast$]{Autour de l'axe de rotation.}}{
        \toprule
            &   \textbf{Premier Solide} &   \textbf{Deuxième Solide}\\
        \midrule
        \textbf{Masse (kg)} &   4,4839  &   3,8177\\
        \multicolumn{3}{c}{\hdashrule{8cm}{1pt}{1pt 5pt}} \\
        \textbf{Centre de masse\tmark[$\ast$] ($\bm{x}\,;\, \bm{y}$) (m)}   &   (0 ; 0,1940)    & (0 ; 0,1613)\\
        \multicolumn{3}{c}{\hdashrule{8cm}{1pt}{1pt 5pt}} \\
        \textbf{Moment d'inertie\tmark[$\ast \ast$] (kg$\cdot$m\textsuperscript 2)}&    0,0913  &   0,0615\\
        \bottomrule}

\end{document}

Unfortunately, these dashed lines don't adjust automatically to the table width, and even worse, they do not conserve the vertical spacing between rows!

Is there a way to make this simple and automatic?

Note : I also tried replacing

\multicolumn{3}{c}{\hdashrule{8cm}{1pt}{1pt 5pt}}

by

\hdashline[1pt/3pt]

\hdashline has the advantage to automatically adjust to the table width, but it doesn't conserve the booktabs vertical spacing laws. Also, one can't control the size of the dashed line using this command.

Answer 1

new version keeping the rule within the table

\documentclass[10pt]{book}
\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}
\usepackage{multicol,bm}
\usepackage{array, booktabs}
\usepackage{ctable, dashrule}

 \usepackage[left=2cm, right=2cm, top=2cm, bottom=2cm]{geometry}

\makeatletter

\def\xmidrule{%
\noalign{\vskip\aboverulesep}%
\multispan{3}{\leaders\hbox to 4pt{\hss\vrule\@height\cmidrulewidth\@width 2pt \relax\hss}\hfill\kern0pt}\cr%
\noalign{\vskip\belowrulesep}%
}
\makeatother

\begin{document}


\noindent X \dotfill X

\ctable[caption= {Paramètres},
        label  = {tab:paramètres},
        ]
        {m{6.cm} m{3.5cm} l }
        {\tnote[$\ast$]{Dans le repère du solide.} \tnote[$\ast \ast$]{Autour de l'axe de rotation.}}{
        \toprule
            &   \textbf{Premier Solide} &   \textbf{Deuxième Solide}\\
        \midrule
        \textbf{Masse (kg)} &   4,4839  &   3,8177\\
        \xmidrule
        \textbf{Centre de masse\tmark[$\ast$] ($\bm{x}\,;\, \bm{y}$) (m)}   &   (0 ; 0,1940)    & (0 ; 0,1613)\\
        \multicolumn{3}{c}{\hdashrule{8cm}{1pt}{1pt 5pt}} \\
        \textbf{Moment d'inertie\tmark[$\ast \ast$] (kg$\cdot$m\textsuperscript 2)}&    0,0913  &   0,0615\\
        \bottomrule}

\end{document}