创建自定义规则

Question

当我试图回答时，我如何自定义 fbox 和 hrule？，我尝试使用基本的 LaTeX 命令来执行此操作，如下面的 MWE 所示。但由于某种原因，该命令\egline没有生成与相同的输出\sampleline。这是为什么？

\documentclass[letterpaper]{article}
\usepackage{xcolor}
\usepackage{lipsum}
\newcommand{\egline}{%
    \par\vskip 1ex%
    {\color{ejemplo}%
    \leavevmode\hrule height 1pt width \dimexpr\hsize-2em\relax \hrule height 0.5ex width 2em%
    }%
    \par\vskip1ex%
    }
\definecolor{ejemplo}{RGB}{37,153,116}
\newcommand{\sampleline}{%
    \par\noindent%
    {\color{ejemplo}%
    \parbox{\linewidth}{%
        \hrulefill\rule{2em}{0.5ex}}%
        }%
    \par%
}
\begin{document}
\lipsum[1-2]
\egline
\sampleline
\lipsum[1-2]
\end{document}

---

我重新定义命令\egline如下：

\newcommand{\egline}{%
    \par\vskip 1ex%
    {%
    \color{ejemplo}%
    \leavevmode%
    \vbox{%
    \hrule height 1pt width \dimexpr\hsize-2em\relax}%
    \vbox{%
     \hrule height 0.5ex width 2em}%
    }%
    \par\vskip1ex%
    }

但它给出了额外的空白（水平方向 15pt）？奇怪吗？参见下图：

---

按照戴维·卡莱尔 (David Carlisle) 的建议进行第三次定义，我对上述问题进行了简单的修复，但我仍然不明白是什么导致了缩进。

\newcommand{\egline}{%
    \par\vskip 1ex%
    {%
    \color{ejemplo}%
    \hskip-15pt\leavevmode\vrule height 1pt width \dimexpr\hsize-2em\relax\vrule height 0.5ex width 2em%
    }%
    \par\vskip1ex%
    }

---

总而言之，修复方法\noindent是\leavevmode：

\noindent\vrule height 1pt width \dimexpr\hsize-2em\relax\vrule height 0.5ex width 2em%

Answer 1

\newcommand{\egline}{%
    \par\vskip 1ex%
% here you are in vertical mode
    {%
%here you put a colour whatsit on the vertical list (best to avoid that if possible)
\color{ejemplo}%
% here you start a paragraph and get into horizontal mode

    \leavevmode
% \hrule isn't allowed in hmode, so this ends the (blank) paragraph and gets back to vmode
\hrule height 1pt width \dimexpr\hsize-2em\relax
% as we are in vmode this rule comes under the previous one
 \hrule height 0.5ex width 2em%
    }%
% another color whatsit gets inserted here (again on a vertical list)
    \par\vskip1ex%
    }