如何在投影機部分導覽列中的當前部分和其他部分使用不同的背景顏色

Question

我使用以下程式碼建立部分導覽列：

\setbeamercolor{section in head/foot}{bg=blue,fg=white}
\addtobeamertemplate{footline}{%
    \leavevmode%
    \hbox{%
        \begin{beamercolorbox}[wd=\paperwidth,ht=2.25ex,dp=1ex,center]{section in head/foot}%
            \insertsectionnavigationhorizontal{\paperwidth}{}{}
        \end{beamercolorbox}}%

}{}

現在導覽列的背景為藍色，目前部分為白色字體，其他部分為灰色字體。但是它們可以有不同的背景顏色嗎？例如目前部分為深藍色背景，其他部分為淺藍色背景？

整個 beamer tex 檔案就是這個非常小的檔案。

\documentclass{beamer}

\usetheme{Madrid}
\title{Title}
\author{Author}
\date{\today}
\addtobeamertemplate{footline}{%
    \leavevmode%
    \hbox{%
        \begin{beamercolorbox}[wd=\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
            \insertsectionnavigationhorizontal{\paperwidth}{}{}
        \end{beamercolorbox}}%

}{}

\begin{document}
\titlepage
\section{Sec 1}
\begin{frame}{Frame Title}{Frame Subtitle}
    Frame contents
    \begin{itemize}
        \item Item 1
        \item Item 2
              \begin{itemize}
                  \item Subitem 2.1
                  \item Subitem 2.2
              \end{itemize}
    \end{itemize}
    This is \textbf{bold text for normal text}.
\end{frame}

\section{Sec 2}
\begin{frame}{Frame Title}{Frame Subtitle}
    \begin{block}{Block}
        This is \textbf{bold text for blocks}.
    \end{block}
    \begin{alertblock}{Alert Block}
        This is \textbf{bold text for alert blocks}.
    \end{alertblock}
    \begin{example}
        This is \textbf{bold text for example blocks}.
    \end{example}
    \begin{block}{}
        \centering
        This is \textbf{bold text for unnamed blocks}.
    \end{block}
\end{frame}

\end{document}

結果是

不難看出，導覽列中的 sec 1 和 sec 2 似乎屬於一個完整的長水平條，它們之間沒有任何邊界。它們共享相同的背景顏色，只是突出顯示當前的顏色。我想為他們製作不同的背景顏色。那可能嗎？

Answer 1

您可以重新定義section in head/foot (shaded)模板以包含某種顏色框：

\documentclass{beamer}

\usetheme{Madrid}
\title{Title}
\author{Author}
\date{\today}

\addtobeamertemplate{footline}{%
    \leavevmode%
    \hbox{%
        \begin{beamercolorbox}[wd=\paperwidth,ht=2.5ex,dp=1.1ex,center]{author in head/foot}%
            \insertsectionnavigationhorizontal{\paperwidth}{}{\hskip0pt plus1filll}
        \end{beamercolorbox}}%

}{}

\makeatletter
\newcommand{\secwidth}{\dimexpr\paperwidth/\beamer@sectionmax-2\fboxsep\relax}

\setbeamertemplate{section in head/foot}{\colorbox{orange}{\parbox{\secwidth}{\centering\insertsectionhead}}}
\setbeamertemplate{section in head/foot shaded}{\colorbox{cyan}{\parbox{\secwidth}{\centering\insertsectionhead}}}

\def\insertsectionnavigationhorizontal#1#2#3{%
  \hbox to #1{{%
     \def\slideentry##1##2##3##4##5##6{}%
     #2%\hskip.3cm%
     \usebeamerfont{section in head/foot}\usebeamercolor[fg]{section in head/foot}%
     \setbox\beamer@sectionbox=\hbox{}%
     \ht\beamer@sectionbox=1.875ex%
     \dp\beamer@sectionbox=0.75ex%
     \dohead%
     \box\beamer@sectionbox\hfil%\hskip.3cm%
     #3}}}
     
\def\sectionentry#1#2#3#4#5{% section number, section title, page
  \beamer@xpos=0\relax%
  \beamer@ypos=1\relax%
  \beamer@ypos@offset=0\relax%
  \ifnum#5=\c@part%
  \beamer@section@set@min@width%
  \box\beamer@sectionbox\hskip0ex plus 1fill%
  \setbox\beamer@sectionbox=
  \hbox{\def\insertsectionhead{#2}%
    \def\insertsectionheadnumber{#1}%
    \def\insertpartheadnumber{#5}%
    {%
      \usebeamerfont{section in head/foot}\usebeamercolor[fg]{section in head/foot}%
      \ifnum\c@section=#1%
        \hyperlink{Navigation#3}{{\usebeamertemplate{section in head/foot}}}%
      \else%
        \hyperlink{Navigation#3}{{\usebeamertemplate{section in head/foot shaded}}}%
      \fi}%
  }%
  \ht\beamer@sectionbox=1.875ex%
  \dp\beamer@sectionbox=0.75ex%
  \fi\ignorespaces}     
\makeatother

\begin{document}

\section{Sec 1}
\begin{frame}
\end{frame}

\section{Sec 2}
\begin{frame}
\end{frame}

\section{Sec 3}
\begin{frame}
\end{frame}

\end{document}