以下是我的问题的更新，显示了我的真实意思：
我想给我的内小頁面。
但\fbox缩进小页面，导致overfull hbox错误
\documentclass{beamer}
\usepackage{showframe}
\begin{document}
\begin{frame} %works fine
\begin{center}
a
\begin{minipage}{0.4\textwidth}
\hfill
b
\begin{minipage}{\textwidth}
\begin{itemize}
\item one
\end{itemize}
\end{minipage}
\end{minipage}
\hfill
\begin{minipage}{0.4\textwidth}
c
\begin{minipage}{\textwidth}
\begin{itemize}
\item two
\end{itemize}
\end{minipage}
\end{minipage}
d
\end{center}
\end{frame}
\begin{frame} %overfull hbox
\begin{center}
a
\begin{minipage}{0.4\textwidth}
\hfill
b
\fbox{\begin{minipage}{\textwidth}
\begin{itemize}
\item one
\end{itemize}
\end{minipage}}
\end{minipage}
\hfill
\begin{minipage}{0.4\textwidth}
c
\fbox{\begin{minipage}{\textwidth}
\begin{itemize}
\item two
\end{itemize}
\end{minipage}}
\end{minipage}
d
\end{center}
\end{frame}
\end{document}
答案1
以下是有和没有framed环境的几种解决方案：
\documentclass{article}
\usepackage[showframe]{geometry}
\usepackage{framed}
\begin{document}
\fbox{\begin{minipage}{0.4\textwidth} % fbox only for showing problem
% insert some tikz picture
\noindent
\fbox{\begin{minipage}{\dimexpr\linewidth-2\fboxsep-2\fboxrule}
some text
\end{minipage}}
\end{minipage}}
\hfill
\fbox{\begin{minipage}{0.4\textwidth} % fbox only for showing problem
% insert some tikz picture
\begin{framed}\begin{minipage}{\linewidth}
some other text
\end{minipage}\end{framed}
\end{minipage}}
\fbox{\begin{minipage}{0.4\textwidth} % fbox only for showing problem
% insert some tikz picture
\begin{minipage}{\linewidth}\begin{framed}
some other text
\end{framed}\end{minipage}
\end{minipage}}
\end{document}
