带圆圈的字符的左右字符间距为零

Question

平均能量损失

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usepackage{pgflibraryshapes}
\newcommand*\circled[1]{%
\tikz[baseline=(x.base)]
\node[draw,red,circle,thick,fill=white,inner sep=2pt](x) {$\displaystyle#1$};}

\begin{document}
a\circled{b}a
\end{document}

但我尝试做的

你能帮我修复它吗？

Answer 1

您可以使用overlay（进行一些宽度调整）。

\documentclass[12pt]{article}
\newlength{\mywida}
\newlength{\mywidb}
\newlength{\mywidback}
\usepackage{tikz}
\newcommand{\circled}[2]{\phantom{\emph{#1}}#2%
    \settowidth{\mywida}{#2}%
    \settowidth{\mywidb}{\emph{#1}}%
    \setlength{\mywidback}{.5\mywidb}%
    \addtolength{\mywidback}{\mywida}%
    \hspace{-\mywidback}%
    \tikz[baseline=(x.base), overlay]
    \node[draw,red,circle,thick,inner sep=2pt] (x) {\emph{#1}};%
    \hspace{\mywidback}%
}
\begin{document}
    a\circled{b}{a} another exam\circled{p}{le}
\end{document}