如何像图片中那样绘制并突出显示文本？

Question

如何通过tikz包装来绘制这样的图？

Answer 1

以下是彩虹的示例：

\documentclass{article}
\usepackage{mathtools}
\usepackage{array}
\setlength{\extrarowheight}{4pt}
\newcolumntype{M}[1]{>{\centering\arraybackslash}m{#1}}

\usepackage{tikz}
\tikzset{every picture/.style={remember picture}}
\newcommand{\fromhere}[3]{\tikz[baseline]{\node[rounded corners, fill=#3, anchor=base, text height=1.45ex,text depth=.1ex] (#1) {#2};}}
\newcommand{\tohere}[2]{\tikz[baseline]{\node[anchor=base, inner xsep=-1pt,inner ysep=0pt] (#1) {$#2$};}}

\begin{document}
    \begin{center}
        \begin{tabular}{|M{7em}|M{25em}|}
            \hline
            \TeX.SE problem & 
            Why do so \fromhere{dn1}{many users}{red} not post an MWE (minimal working example)? Because they don't know \fromhere{du11}{what}{green} it is, they don't know \fromhere{du21}{how}{cyan} to build it or sometimes because they are loo \fromhere{du31}{lazy}{pink}\dots 

            On the contrary, which are the \fromhere{dn2}{smart users'}{yellow} golden rules of problem-solving? Read the \fromhere{du12}{manual}{orange}, search on \fromhere{du22}{TeX.SE}{lime} or, in general, on the Internet, and always post an \fromhere{du32}{MWE}{brown}!\\
            \hline
            van Duck's equations & 
            $\tohere{u11}{u_{1}^{1}} +
            \tohere{u21}{u_{2}^{1}} + 
            \tohere{u31}{u_{3}^{1}} -
            \tohere{n1}{n^{1}} = 0 \qquad 
            \tohere{u12}{u_{1}^{2}} +
            \tohere{u22}{u_{2}^{2}} +
            \tohere{u32}{u_{3}^{2}} -
            \tohere{n2}{n^{2}}  = 0$ \\
            \hline
        \end{tabular}
    \end{center}
    \begin{tikzpicture}[overlay]
        \draw[red,thick] ([xshift=2em]dn1.south) -- (n1.north);
        \draw[green,thick] ([xshift=-4pt]du11.south) -- (u11.north);
        \draw[cyan,thick] (du21.south) -- (u21.north);
        \draw[pink,thick] ([xshift=-9pt]du31.south) -- (u31.north);
        \draw[yellow,thick] ([xshift=2.3em]dn2.south) -- (n2.north);
        \draw[orange,thick] (du12.south) -- (u12.north);
        \draw[lime,thick] (du22.south) -- (u22.north);
        \draw[brown,thick] ([xshift=8pt]du32.south) -- (u32.north);
    \end{tikzpicture}
\end{document}