我是 Latex 的新手，正在通过使用模板和尝试各种参数和参数来学习更多工具。
因此，我尝试使用以下 tikz 构造来对定理进行装箱
\newcounter{theorem}[chapter] \setcounter{theorem}{0}
\renewcommand{\thetheorem}{\arabic{chapter}.\arabic{theorem}}
\newenvironment{theorem}[2][]{%
\refstepcounter{theorem}%
\ifstrempty{#1}%
{\mdfsetup{%
frametitle={%
\tikz[baseline=(current bounding box.east),outer sep=.5pt]
\node()[anchor=east,rectangle,fill=blue!20]
{\strut Theorem~\thetheorem};}}
}%
{\mdfsetup{%
frametitle={%
\tikz[baseline=(current bounding box.east),outer sep=.5pt]
\node()[anchor=east,rectangle,fill=red!20]
{\strut Theorem~\thetheorem:~#1};}}%
}%
\mdfsetup{innertopmargin=5pt,linecolor=blue!20,%
linewidth=2pt,topline=true,%
frametitleaboveskip=\dimexpr-\ht\strutbox\relax
}
\begin{mdframed}[]\relax%
\label{#2}}{\end{mdframed}}
这样做会遮挡定理陈述中的前几个字母。此外，它经常会以丑陋的方式分裂到不同的页面上。我尝试调整参数和边距等，但无济于事。
有没有办法来解决这个问题？
这是一个示例文档，您可以复制并编译它来亲自查看错误。
\documentclass[15pt]{book}
\usepackage[framemethod=TikZ]{mdframed}
\usepackage{,tikz- cd,amssymb,amsmath,amsthm,amsfonts,sectsty,url,graphicx,MnSymbol,algorithm,listings,color,appendix,mathrsfs,makeidx}
\usepackage[letterpaper,hmargin=1.0in,vmargin=1.0in]{geometry}
\usepackage[Bjornstrup]{fncychap}
\pagestyle{plain}
\makeindex
\newcounter{theorem}[chapter] \setcounter{theorem}{0}
\renewcommand{\thetheorem}{\arabic{chapter}.\arabic{theorem}}
\newenvironment{theorem}[2][]{%
\refstepcounter{theorem}%
\ifstrempty{#1}%
{\mdfsetup{%
frametitle={%
\tikz[baseline=(current bounding box.east),outer sep=.5pt]
\node()[anchor=east,rectangle,fill=blue!20]
{\strut Theorem~\thetheorem};}}
}%
{\mdfsetup{%
frametitle={%
\tikz[baseline=(current bounding box.east),outer sep=.5pt]
\node()[anchor=east,rectangle,fill=red!20]
{\strut Theorem~\thetheorem:~#1};}}%
}%
\mdfsetup{innertopmargin=5pt,linecolor=blue!20,%
linewidth=2pt,topline=true,%
frametitleaboveskip=\dimexpr-\ht\strutbox\relax
}
\begin{mdframed}[]\relax%
\label{#2}}{\end{mdframed}}
\begin{document}
\title{
\textbf{Test Document}}
\author{
\Large{Latex n00b}}
\setlength{\parskip}{1ex plus 0.5ex minus 0.2ex}
\maketitle
\chapter{First Chapter}
So as I mentioned, the tikz theorem box as defined above cuts the first letter of the theorem statement. It also splits across pages in an ugly way.
\begin{theorem}
For $p$ be a prime,
$$a^{p-1} \equiv 1 \pmod p$$
\end{theorem}
It also shows errors when the theorem statement comprises only an equation.
\begin{theorem}
$$\sum \limits_{i=1}^{n} i = \frac{n(n+1)}{2}$$
\end{theorem}
\end{document}
答案1
在您的代码中，定理定义以此开头：
\newenvironment{theorem}[2][]{%
这意味着环境将有一个最初为空的可选参数和一个强制参数。因此，你的定理环境应该是：
\begin{theorem}{...} %<--- No optional parameter and one mandatory
theorem contents
\end{theorem}
由于您没有包含强制参数，因此将使用定理内容的第一个字母作为强制参数。一旦添加，{}问题就会消失。
正如你所说，你正在学习 LaTeX，也许你会对tcolorbox包提供了一个用于盒装定理的特殊库。以下代码显示了如何使用重现定理格式tcolorbox。
在本例中，\newtcolorbox声明了一个名为的定理环境myTheorem，它将具有两个强制参数，第一个是定理标题，第二个是标签后缀。同一命令还定义了一个myTheorem*未编号定理的环境。
\documentclass[15pt]{book}
\usepackage[most]{tcolorbox}
\newtcbtheorem[number within=chapter]{myTheorem}{THEOREM}{%
enhanced,
sharp corners,
colframe=blue!20,
colback=white,
colbacktitle=blue!20,
coltitle=black,
boxed title style={sharp corners},
attach boxed title to top left={xshift=5mm,yshift*=-\tcboxedtitleheight/2},
}{th}
\begin{document}
\chapter{First chapter}
\begin{myTheorem*}{}{}
For $p$ be a prime,
\[a^{p-1} \equiv 1 \pmod p\]
\end{myTheorem*}
\begin{myTheorem}{This is another theorem}{NT}
\[\sum_{i=1}^{n} i = \frac{n(n+1)}{2}\]
\end{myTheorem}
As you can see in Theorem~\ref{th:NT}
\end{document}
