Beamer：页脚显示当前幻灯片编号但没有总幻灯片编号；如何修改？

Question

我使用信息线作为外部主题，我很喜欢它。我想只显示当前幻灯片编号，而不显示总幻灯片编号。

我找到了 Gonzalo Medina 提供的以下答案。非常好。

但是，我怎样才能从 footline 左侧面板中删除 0，如下图所示。

\documentclass{beamer}
\usetheme{Warsaw}
\useoutertheme{infolines}

\makeatletter
\setbeamertemplate{footline}
{
  \leavevmode%
  \hbox{%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
    \usebeamerfont{author in head/foot}\insertshortauthor~~\beamer@ifempty{\insertshortinstitute}{}{(\insertshortinstitute)}
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,center]{title in head/foot}%
    \usebeamerfont{title in head/foot}\insertshorttitle
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,right]{date in head/foot}%
    \usebeamerfont{date in head/foot}\insertshortdate{}\hspace*{2em}
    \insertframenumber\hspace*{2ex} 
  \end{beamercolorbox}}%
  \vskip0pt%
}
\makeatother


\begin{document}

\begin{frame}Test\end{frame}
\begin{frame}Test\end{frame}
\begin{frame}Test\end{frame}

\end{document}

Answer 1

事实上，“0”并不是一个“0”，而是一个空括号。要删除它，可以定义一个机构，\institute{where ever you want to be}或者使用例如这样的方法：

\documentclass{beamer}
\usetheme{Warsaw}
\useoutertheme{infolines}

\makeatletter
\setbeamertemplate{footline}
{
  \leavevmode%
  \hbox{%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
    \usebeamerfont{author in head/foot}\insertshortauthor
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,center]{title in head/foot}%
    \usebeamerfont{title in head/foot}\insertshorttitle
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,right]{date in head/foot}%
    \usebeamerfont{date in head/foot}\insertshortdate{}\hspace*{2em}
    \insertframenumber\hspace*{2ex} 
  \end{beamercolorbox}}%
  \vskip0pt%
}
\makeatother

\begin{document}

\begin{frame}Test\end{frame}
\begin{frame}Test\end{frame}
\begin{frame}Test\end{frame}

\end{document}