这个答案展示了如何修改定理环境以避免在定理标题后出现换行符（当垂直空间是一种宝贵的商品时，这很有用）。
我想修改该答案，以便定理标题的文本（我的意思是文本“定理 1.1 (ABC)”）尊重警报。以下是基于该主题中的答案的示例：
\documentclass[envcountsect]{beamer}
\usetheme{CambridgeUS}
\usefonttheme{serif}
\usepackage{etoolbox}
\makeatletter
\setbeamertemplate{theorem begin}
{%
\begin{\inserttheoremblockenv}
{}{\usebeamerfont*{block title}\usebeamercolor[fg]{block title}%
\inserttheoremname
\inserttheoremnumber
\ifx \inserttheoremaddition \empty \else\ (\inserttheoremaddition)\fi
\inserttheorempunctuation}
\normalfont
}
\setbeamertemplate{theorem end}{\end{\inserttheoremblockenv}}
\makeatother
\begin{document}
\section{ABC}
\begin{frame}
\begin{alertenv}<+>
\begin{theorem}[ABC]
This is a theorem
\end{theorem}
\end{alertenv}
\begin{theorem}[DEF]
This is a another theorem (not alerted).
\end{theorem}
Text.
\begin{block}{Block title}
A block with title.
\end{block}
Text.
\begin{block}{}
A block without title.
\end{block}
\end{frame}
\end{document}
请注意使用颜色“块标题”的代码。因此，在警报模式下，它仍然使用“块标题”。当文本需要警报时，如何使用“块标题警报”？也就是说，在示例文件中，我希望“定理 1.1 (ABC)”采用警报颜色，而“定理 1.2 (DEF)”采用非警报颜色。
答案1
如果您使用定理标题的默认蓝色，则可以用- 一种会被警报环境改变的颜色替换该block title颜色：local structure
\documentclass[envcountsect]{beamer}
\usetheme{CambridgeUS}
\usefonttheme{serif}
\usepackage{etoolbox}
\makeatletter
\setbeamertemplate{theorem begin}
{%
\begin{\inserttheoremblockenv}
{}{\usebeamerfont*{block title}\usebeamercolor[fg]{local structure}%
\inserttheoremname
\inserttheoremnumber
\ifx \inserttheoremaddition \empty \else\ (\inserttheoremaddition)\fi
\inserttheorempunctuation}
\normalfont
}
\setbeamertemplate{theorem end}{\end{\inserttheoremblockenv}}
\makeatother
\begin{document}
\section{ABC}
\begin{frame}
\begin{alertenv}<+>
\begin{theorem}[ABC]
This is a theorem
\end{theorem}
\end{alertenv}
\begin{theorem}[DEF]
This is a another theorem (not alerted).
\end{theorem}
Text.
\begin{block}{Block title}
A block with title.
\end{block}
Text.
\begin{block}{}
A block without title.
\end{block}
\end{frame}
\end{document}
如果您对块标题和/或结构使用特殊颜色，则可以告诉警报环境更改块标题颜色：
\documentclass[envcountsect]{beamer}
\usetheme{CambridgeUS}
\usefonttheme{serif}
\usepackage{etoolbox}
\makeatletter
\setbeamertemplate{theorem begin}
{%
\begin{\inserttheoremblockenv}
{}{\usebeamerfont*{block title}\usebeamercolor[fg]{block title}%
\inserttheoremname
\inserttheoremnumber
\ifx \inserttheoremaddition \empty \else\ (\inserttheoremaddition)\fi
\inserttheorempunctuation}
\normalfont
}
\setbeamertemplate{theorem end}{\end{\inserttheoremblockenv}}
\addtobeamertemplate{alerted text begin}{}{%
\setbeamercolor{block title}{parent=alerted text}%
}
\makeatother
\begin{document}
\section{ABC}
\begin{frame}
\begin{alertenv}<+>
\begin{theorem}[ABC]
This is a theorem
\end{theorem}
\end{alertenv}
\begin{theorem}[DEF]
This is a another theorem (not alerted).
\end{theorem}
Text.
\begin{block}{Block title}
A block with title.
\end{block}
Text.
\begin{block}{}
A block without title.
\end{block}
\end{frame}
\end{document}
