我正在尝试为我的大学改编一个非官方的 Beamer 模板（GitHub，背页）。现在，当我尝试编译这个MWE时：
\documentclass{beamer}
\usetheme[bgphoto]{polimi}
\title[MS thesis]{Thesis title}
\subtitle{Master Thesis in Computer Science and Engineering}
\author[Alessandro Bertulli]{Alessandro Bertulli, matr. xxxxxx}
\date[05/10/2023]{5th October 2023}
\begin{document}
\begin{frame}
\maketitle
\end{frame}
\section{Introduction}
\begin{frame}[plain]{}
\sectionpage
\end{frame}
\end{document}
我得到这个为sectionpage：
我想要删除标题，IIUC 应该使用 as 选项的效果plain。显然，这只有在它不是标题后的第一张幻灯片时才有效，如第二个 MWE 所示：
\documentclass{beamer}
\usetheme[bgphoto]{polimi}
\title[MS thesis]{Thesis title}
\subtitle{Master Thesis in Computer Science and Engineering}
\author[Alessandro Bertulli]{Alessandro Bertulli, matr. xxxxxx}
\date[05/10/2023]{5th October 2023}
\begin{document}
\begin{frame}
\maketitle
\end{frame}
\begin{frame}
\end{frame}
\section{Introduction}
\begin{frame}[plain]{}
\sectionpage
\end{frame}
\end{document}
这使
原因何在？谢谢！
为了完整性，我在这里发布样式文件：
beamerthemepolimi.sty：
% Pasquale Africa <[email protected]>
% Beamer port of the official PoliMi presentation theme.
\mode<all>
\newif\if@bgphoto
\@bgphotofalse
\DeclareOption{bgphoto}{\@bgphototrue}
\newif\if@nologo
\@nologofalse
\DeclareOption{nologo}{\@nologotrue}
\ProcessOptions
\RequirePackage{tikz}
\usetikzlibrary{calc}
\graphicspath{{beamerthemepolimi_img/}}
\RequirePackage{etoolbox} % \patchcmd
\useinnertheme{polimi}
\useoutertheme{polimi}
\usecolortheme{polimi}
\setbeamertemplate{navigation symbols}{}
\setbeamertemplate{blocks}[rounded][shadow=true]
\setbeamertemplate{itemize items}[square]
\setbeamertemplate{itemize subitem}[triangle]
% Set margins.
\setbeamersize{text margin left=\xshift, text margin right=\xshift}
\setlength{\leftmargini}{\xshift}
\let\oldtoc\tableofcontents
\renewcommand{\tableofcontents}[1][]{%
\hspace*{0.5\xshift}
\begin{minipage}{\textwidth}
\oldtoc[#1]
\end{minipage}
}
beamerouterthemepolimi.sty
\mode<presentation>
\newlength{\xshift}
\setlength{\xshift}{0.05\paperwidth}
% Header.
\defbeamertemplate*{frametitle}{polimi}
{
\begin{tikzpicture}[overlay, remember picture]
\node at ([shift={(\xshift, -0.6)}] current page.north west) [anchor=south west, inner sep=0pt]
{
{\small \insertsectionhead \ifx\insertsubsection\empty\else\ - \insertsubsectionhead\fi\leavevmode}
};
\node at ([shift={(\xshift, -1.25)}] current page.north west) [anchor=south west, inner sep=0pt]
{
\insertframetitle
};
\end{tikzpicture}
\vspace{1.1cm}
}
% Header.
\defbeamertemplate*{frametitle}{plain}{}
% Use frametitle template even if \frametitle is empty.
\patchcmd{\endbeamer@frameslide}{\ifx\beamer@frametitle\@empty}{\iffalse}{}{\errmessage{Failed to patch frametitle.}}
% Footer.
\defbeamertemplate{footline}{polimi}{
\begin{minipage}[b][1cm][c]{\paperwidth}
\ifnum\c@framenumber>0
\begin{tikzpicture}[overlay, remember picture]
\node at ([shift={(\xshift, 0.5)}] current page.south west) [anchor=west, inner sep=0pt]
{
{\scriptsize\color{white} \insertauthor}
};
\node at ([shift={(-0.5\xshift, 0.5)}] current page.south east) [anchor=east, inner sep=0pt]
{
\includegraphics[height=\baselineskip]{logo_bandiera.png}
};
\end{tikzpicture}
\fi
\end{minipage}
}
\setbeamertemplate{footline}[polimi]
% Enable nonumber option.
\BeforeBeginEnvironment{frame}{
\setbeamertemplate{background}[polimi]
\setbeamertemplate{frametitle}[polimi]
\setbeamertemplate{headline}[frame number]
}
\makeatletter
\define@key{beamerframe}{nonumber}[true]{
\setbeamertemplate{headline}{}
\addtocounter{framenumber}{-1}
}
\makeatother
% Enable plain option.
\makeatletter
\define@key{beamerframe}{plain}[true]{
\ifnum\c@framenumber>0
\setbeamertemplate{background}[footer]
\setbeamertemplate{frametitle}[plain]
\setbeamertemplate{headline}{}
\addtocounter{framenumber}{-1}
\fi
}
\makeatother
beamerinnerthemepolimi.sty
\mode<presentation>
% Background.
\defbeamertemplate*{background}{polimi}{
% Titlepage.
\ifnum\c@framenumber=0
\begin{tikzpicture}[overlay, remember picture]
\if@bgphoto
\node at (current page.north) [anchor=north, inner sep=0pt] {\includegraphics[width=\paperwidth]{bgphoto_cut.jpg}};
\fi
\node (foot) at (current page.south) [anchor=south, minimum width=\paperwidth, minimum height=0.4415\paperheight, fill=bluePolimi] {};
\if@nologo\else
\node at (foot.north) [anchor=south, inner sep=0.5cm] {
\if@bgphoto
\includegraphics[width=0.3\paperwidth]{logo_centrato_COL_negativo.png}
\else
\includegraphics[width=0.3\paperwidth]{logo_centrato_COL_positivo.png}
\fi
};
\fi
\node at ([shift={(0, -0.1)}] foot.north) {\includegraphics[width=\paperwidth]{decoration.pdf}};
\end{tikzpicture}
\else
\begin{tikzpicture}[overlay, remember picture]
\node (head) at (current page.north) [anchor=north, minimum width=\paperwidth, minimum height=0.1835\paperheight, fill=bluePolimi] {};
\node at ([shift={(0, 0.1)}] head.south) {\includegraphics[width=\paperwidth]{decoration.pdf}};
\node (foot) at (current page.south) [anchor=south, minimum width=\paperwidth, minimum height=0.105\paperheight, fill=bluePolimi] {};
\end{tikzpicture}
\fi
}
% Only footer background.
\defbeamertemplate*{background}{footer}{
\begin{tikzpicture}[overlay, remember picture]
\node (foot) at (current page.south) [anchor=south, minimum width=\paperwidth, minimum height=0.105\paperheight, fill=bluePolimi] {};
\end{tikzpicture}
}
% Title page.
\defbeamertemplate*{title page}{polimi}[1][]
{
\color{white}
\vspace{4.25cm}
\begin{minipage}[t][\baselineskip]{\paperwidth}
{\Large\bf \inserttitle}
\end{minipage}
\\[\baselineskip]
\begin{minipage}[t][2\baselineskip]{\paperwidth}
{\large \insertsubtitle}
\end{minipage}
\vfill
\begin{minipage}[t][\baselineskip]{\paperwidth}
{\large\bf \insertauthor}
\end{minipage}
\begin{minipage}[t][\baselineskip]{\paperwidth}
\insertdate
\end{minipage}
\vfill
\addtocounter{framenumber}{-1}
}
% Table of Contents.
\setbeamertemplate{section in toc}[circle]
\setbeamertemplate{subsection in toc}{\leavevmode \leftskip=0.7em {\color{bluePolimi} $\bullet$} \hskip1pt \inserttocsubsection\par}
% Section page.
\defbeamertemplate*{section page}{polimi}{
\begin{tikzpicture}[overlay, remember picture]
\node (foot) at (current page.south) [anchor=south, minimum width=\paperwidth, minimum height=0.4415\paperheight, fill=bluePolimi] {};
\node at ([shift={(0, -0.1)}] foot.north) {\includegraphics[width=\paperwidth]{decoration.pdf}};
% \path let \p1 = ([shift={(0, 0.105\paperheight+0.25)}] current page.south west), \p2 = (current page.east) in (\x1, \y1) edge [white, line width=0.5] (\x2, \y1);
\node at ([shift={(\xshift, 3.5)}] current page.south west) [anchor=north west, inner sep=0pt, text width=\textwidth]
{
{\color{white}\Large\bf \insertsection}
};
\end{tikzpicture}
}
\setbeamertemplate{section page}[polimi]
% Subsection page.
\defbeamertemplate*{subsection page}{polimi}{
\begin{tikzpicture}[overlay, remember picture]
\node (foot) at (current page.south) [anchor=south, minimum width=\paperwidth, minimum height=0.4415\paperheight, fill=bluePolimi] {};
\node at ([shift={(0, -0.1)}] foot.north) {\includegraphics[width=\paperwidth]{decoration.pdf}};
% \path let \p1 = ([shift={(0, 0.105\paperheight+0.25)}] current page.south east), \p2 = (current page.west) in (\paperwidth,\y1) edge [white, line width=0.5] (\x2,\y1);
\node at ([shift={(\xshift, 3.5)}] current page.south west) [anchor=north west, inner sep=0pt, text width=\textwidth]
{
{\color{white}\Large\bf \insertsubsection}
};
\end{tikzpicture}
}
\setbeamertemplate{subsection page}[polimi]
编辑： beamercolorthemepolimi.sty：
\mode<presentation>
\definecolor{bluePolimi}{RGB}{114, 143, 165}
\definecolor{greenPolimi}{RGB}{0, 110, 0}
\definecolor{redPolimi}{RGB}{180, 0, 0}
\setbeamercolor{frametitle}{fg=white}
\setbeamercolor{normal text}{fg=black,bg=white}
\setbeamercolor{alerted text}{fg=redPolimi}
\setbeamercolor{example text}{fg=greenPolimi}
\setbeamercolor{block title}{bg=bluePolimi, fg=white}
\setbeamercolor{block body}{bg=bluePolimi!10!white, fg=black}
\setbeamercolor{block title alerted}{bg=redPolimi, fg=white}
\setbeamercolor{block body alerted}{bg=redPolimi!10!white, fg=black}
\setbeamercolor{block title example}{bg=greenPolimi, fg=white}
\setbeamercolor{block body example}{bg=greenPolimi!10!white, fg=black}
\setbeamercolor{itemize item}{fg=bluePolimi}
\setbeamercolor{itemize subitem}{fg=bluePolimi}
\setbeamercolor{section in toc}{fg=black}
\setbeamercolor{subsection in toc}{fg=black}
\setbeamercolor{section number projected}{bg=bluePolimi}
\setbeamercolor{page number in head/foot}{fg=white}
答案1
由于某种原因，您的主题重新定义了plain框架选项，使其仅适用于框架编号> 0。同时，它将普通框架的框架编号减少一，这意味着，如果普通框架之前没有正常框架，则其框架编号将是0，因此您的主题不会删除标题。
您可以重新定义重新定义的普通框架选项，使其适用于所有框架，如下所示：
\documentclass{beamer}
\usetheme[bgphoto]{polimi}
\title[MS thesis]{Thesis title}
\subtitle{Master Thesis in Computer Science and Engineering}
\author[Alessandro Bertulli]{Alessandro Bertulli, matr. xxxxxx}
\date[05/10/2023]{5th October 2023}
\makeatletter
\define@key{beamerframe}{plain}[true]{
% \ifnum\c@framenumber>0
\setbeamertemplate{background}[footer]
\setbeamertemplate{frametitle}[plain]
\setbeamertemplate{headline}{}
\addtocounter{framenumber}{-1}
% \fi
}
\makeatother
\begin{document}
\section{Introduction}
\begin{frame}[plain]
\sectionpage
\end{frame}
\begin{frame}[plain]
\sectionpage
\end{frame}
\end{document}