章节标题中缺少章节名称

Question

我使用了https://tex.stackexchange.com/a/34292/77602。但我没有得到章节的标题。由于它article没有章节，我删除了章节内容。所以它是

\documentclass[]{article}
\usepackage{lipsum}
\usepackage[explicit]{titlesec}
\usepackage[table]{xcolor}
\usepackage{tikz}\usetikzlibrary{shapes.misc}
\newcommand\titlebar{%
    \tikz[baseline,trim left=3em,trim right=3cm] {
        \fill [cyan!25] (2.5cm,-1ex) rectangle (\textwidth+3.1cm,2.5ex);
        \node [
        fill=cyan!60!white,
        anchor= base east,
        rounded rectangle,
        minimum height=3.5ex] at (3cm,0) {
            \textbf{\thesection}
        };
    }%
}
\titleformat{\section}{\huge}{\titlebar}{0.1cm}{}
\renewcommand*{\thesection}{\Roman{section}}
\begin{document}

\section{Introduction}
\lipsum[1-2]
\end{document}

我得到这个：

Answer 1

只需删除该explicit选项：

\documentclass[]{article}
\usepackage{lipsum}
\usepackage{titlesec}
\usepackage[table]{xcolor}
\usepackage{tikz}\usetikzlibrary{shapes.misc}

\newcommand\titlebar{%
    \tikz[baseline,trim left=3em,trim right=3cm] {
        \fill [cyan!25] (2.5cm,-1ex) rectangle (\textwidth+3.1cm,2.5ex);
        \node [
        fill=cyan!60!white,
        anchor= base east,
        rounded rectangle,
        minimum height=3.5ex] at (3cm,0) {
            \textbf{\thesection}
        };
    }%
}
\titleformat{\section}{\huge}{\titlebar}{0.1cm}{}
\renewcommand*{\thesection}{\Roman{section}}

\begin{document}

\section{Introduction}
\lipsum[1-2]
\end{document}

或者保留选项并使用

\titleformat{\section}{\huge}{\titlebar}{0.1cm}{#1}