如何在 Beamer 中添加增量后保留标题？

Question

当我尝试增加项目符号点时，标题会显示与该部分包含的帧一样多的部分标题。我希望部分标题仅在下方显示四个点。

我在 Beamer 中有以下标题：

\documentclass{beamer} %

%%%BASICS
\usepackage[utf8]{inputenc}
\usepackage{csquotes}

%%%START THEME SETTINGS
\usetheme{Dresden}
\usecolortheme{beaver}
\usefonttheme{professionalfonts}
\setbeamertemplate{itemize item}{\color{red}$\blacksquare$}
%%%END THEME SETTINGS



%%%START APA
\usepackage[british]{babel}
\usepackage[backend=bibtex,style=authoryear]{biblatex}
\addbibresource{references.bib}
%% APA citing
%% \cite{t} - Uthor und Richter, 2010
%% \textcite{t} - Uthor und Riter (2010)
%% \parencite{t} - (Uthor & Riter, 2010)
%% \parencite[Chapt.~4]{t} - (Uthor & Riter, 2010, S. 15)
%%%END APA

\setbeamertemplate{sidebar right}{}
\setbeamertemplate{footline}{%
\hfill\usebeamertemplate***{navigation symbols}
\hspace{1cm}\insertframenumber{}/\inserttotalframenumber}

我想为要点创建增量：

\begin{frame}

\section{Background}

\textbf{ABC}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{DEF}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{GHI}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{JKL}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

我想将标题保持为“背景”，下面有 3 个点，但我在标题上得到以下内容（“背景”4 次）：

Answer 1

像

\section

这样的分区命令总是必须在框架外使用。切勿将它们放在框架内。

\documentclass{beamer} %

%%%BASICS
\usepackage[utf8]{inputenc}
\usepackage{csquotes}

%%%START THEME SETTINGS
\usetheme{Dresden}
\usecolortheme{beaver}
\usefonttheme{professionalfonts}
\setbeamertemplate{itemize item}{\color{red}$\blacksquare$}
%%%END THEME SETTINGS



%%%START APA
\usepackage[british]{babel}
\usepackage[backend=bibtex,style=authoryear]{biblatex}
\addbibresource{references.bib}
%% APA citing
%% \cite{t} - Uthor und Richter, 2010
%% \textcite{t} - Uthor und Riter (2010)
%% \parencite{t} - (Uthor & Riter, 2010)
%% \parencite[Chapt.~4]{t} - (Uthor & Riter, 2010, S. 15)
%%%END APA

\setbeamertemplate{sidebar right}{}
\setbeamertemplate{footline}{%
\hfill\usebeamertemplate***{navigation symbols}
\hspace{1cm}\insertframenumber{}/\inserttotalframenumber}


\begin{document}

\section{Background}

\begin{frame}



\textbf{ABC}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{DEF}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{GHI}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{JKL}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}


\end{document}