带 Tikz 箭头的数字框示例宏

Question

我想以宏的形式重新创建该图像：

到目前为止我有骨架：

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shapes,snakes}
\usepackage{amsmath,amssymb}

\newcounter{exnum}

\setcounter{exnum}{0}

\newcommand{\Example}[1]{\begin{tikzpicture} \stepcounter{exnum}
   \node [mybox1] (box){%
   \begin{minipage}{\textwidth}
    {#1}
   \end{minipage}
    };
 \node[fancytitle1, right=10pt] at (box.north west) {Example 
     \arabic{exnum}:};
 \end{tikzpicture}}
 \begin{document}

  % Define box and box title style
   \tikzstyle{mybox1} = [draw=red, fill=blue!20, very thick,
    rectangle, rounded corners, inner sep=10pt, inner ysep=20pt]
   \tikzstyle{fancytitle1} =[fill=red, text=white]

 \Example{Text}
 \Example{Text}
 \Example{Text}
 \end{document}

得出的结果为：

我需要有关程序样式的帮助和建议。不确定为什么第一个例子略有偏移？

Answer 1

像这样？

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows.meta}
\tikzset{exbox/.style = {
titlebox/.style = {draw, rounded corners, semithick, fill=white,
                   font=\bfseries, inner sep=5pt,
                   node contents={Exercise~\theex}
                   },
     arr/.style = {{Triangle[angle=45:1pt 3]}-{Triangle[angle=45:1pt 3]}, 
                   rounded corners, semithick},
exercise/.style = {text width=\dimexpr\linewidth-19pt,
                  inner ysep=\baselineskip, inner xsep=5pt,
                  align=justify}
                    }
        }
\newcommand\EX[1]{
    \refstepcounter{ex}
    \noindent%
    \begin{tikzpicture}[exbox]
\node (ex) [exercise] {#1};
    {\lipsum[1]};
    \draw[arr]  ([yshift=-\baselineskip] ex.north west) --
                (ex.north west) --
                (ex.north east) node[titlebox,anchor=west, pos=0.1] --
                ([yshift=-\baselineskip] ex.north east);
    \draw[arr] ([yshift=\baselineskip] ex.south west) --
                (ex.south west) --
                (ex.south east) node[titlebox,anchor=east, pos=0.9] --
                ([yshift=\baselineskip] ex.south east);
\end{tikzpicture}
    \medskip\par}% end new command


\usepackage{lipsum}
\newcounter{ex}

\begin{document}
\EX{\lipsum[1]}
\EX{\lipsum[2]}
\end{document}

Answer 2

一个很好的候选者是tcolorbox。我保留了你的编号方案，exnum但如果你使用类似定理的 tcolorbox，你可能会更好。tcolorbox基于 Ti钾Z 并允许您执行在 Ti 中可以执行的所有操作钾Z 但另外还扩展了对盒子的支持。

\documentclass{article}
\usepackage[most]{tcolorbox}
\newcounter{exnum}
\setcounter{exnum}{0}
\newtcolorbox{exbox}[1][]{%
    enhanced,
    before skip=10ex,
    after skip=10ex,
    frame hidden,
    overlay={%
    \fill[yellow!10,rounded corners=3.14pt]
     ([yshift=2.5ex]frame.north west) rectangle ([yshift=-2.5ex]frame.south
     east);
            \draw[latex-latex,rounded corners=3.14pt] (frame.north west)
             -- ++ (0,2.5ex) -| (frame.north east)
             node[pos=0.06,fill=white,draw,rounded corners]{%
             Example\refstepcounter{exnum} \theexnum};
            \draw[latex-latex,rounded corners=3.14pt] (frame.south west)
             -- ++ (0,-2.5ex) -| (frame.south east)
             node[pos=0.44,fill=white,draw,rounded corners]{Example \theexnum};
    }
}

\begin{document}
    \begin{exbox}
       It is not always true that
       \[ \frac{\partial^2f}{\partial x\,\partial y}(a,b)=
       \frac{\partial^2f}{\partial y\,\partial x}(a,b)\]
    \end{exbox}
    \begin{exbox}
       I am another example
    \end{exbox}
\end{document}