Beamer 中定制的降级框架标题上的圆角

Question

我想要 Beamer 演示文稿中的框架标题：

• 宽度小于paperwidth
• 水平退化
• 有圆角

这个帖子给出了上面描述的前两点。但我不明白如何设置圆角。

如果我添加该行，\setbeamertemplate{frametitle}[rounded corners]则不会发生任何变化。

rounded corners我是否应该在命令中指明参数\defbeamertemplate？如果需要，在哪里？

以下是相关的 MWE：

\documentclass[xcolor={dvipsnames,svgnames,table},10pt]{beamer}

\usepackage[T1]{fontenc}

\colorlet{titleleft}{Red}
\colorlet{titleright}{Green}

\setbeamercolor*{frametitle}{fg=white}

\makeatletter
\pgfdeclarehorizontalshading[titleleft,titleright]{beamer@frametitleshade}{0.7\paperheight}{%
  color(50pt)=(titleleft);
  color(0.85\paperwidth)=(titleright)}

\defbeamertemplate*{frametitle}{horizontal shading}
{%
  \nointerlineskip%
  \vskip+3pt%
  \hbox{\leavevmode
    \advance\beamer@leftmargin by -12bp%
    \advance\beamer@rightmargin by -12bp%
    \beamer@tempdim=\textwidth%
    \advance\beamer@tempdim by \beamer@leftmargin%
    \advance\beamer@tempdim by \beamer@rightmargin%
    \hskip-\Gm@lmargin\hbox{%
      \setbox\beamer@tempbox=\hbox{\begin{minipage}[b]{\paperwidth}%
          \vbox{}\vskip-.75ex%
          \leftskip0.3cm%
          \rightskip0.3cm plus1fil\leavevmode
          \insertframetitle%
          \ifx\insertframesubtitle\@empty%
            \strut\par%
          \else
            \par{\usebeamerfont*{framesubtitle}{\usebeamercolor[fg]{framesubtitle}\insertframesubtitle}\strut\par}%
          \fi%
          \nointerlineskip
          \vbox{}%
          \end{minipage}}%
      \beamer@tempdim=\ht\beamer@tempbox%
      \advance\beamer@tempdim by 2pt%
      \begin{pgfpicture}{0pt}{0pt}{\paperwidth}{\beamer@tempdim}
        \usebeamercolor{frametitle right}
        \pgfpathrectangle{\pgfpointorigin}{\pgfpoint{\paperwidth}{\beamer@tempdim}}
        \pgfusepath{clip}
        \pgftext[left,base]{\pgfuseshading{beamer@frametitleshade}}
      \end{pgfpicture}
      \hskip-\paperwidth%
      \box\beamer@tempbox%
    }%
    \hskip-\Gm@rmargin%
  }%
    \vskip-2pt
}
\makeatother

\setbeamertemplate{frametitle}[rounded corners]

\begin{document}

\begin{frame}{$\hspace{5em}$\textbf{Test}}
 a Test frame
\end{frame}

\end{document}

Answer 1

为了获得圆角，我用 替换了\pgfpathrectangle{}{}。\pgfpathrectanglecorners{}{}我没有找到您指定自定义框架标题的宽度的位置，因此您可能需要将.2和调整.8为您实际想要的。

\documentclass[xcolor={dvipsnames,svgnames,table},10pt]{beamer}

\usepackage[T1]{fontenc}

\colorlet{titleleft}{Red}
\colorlet{titleright}{Green}

\setbeamercolor*{frametitle}{fg=white}

\makeatletter
\pgfdeclarehorizontalshading[titleleft,titleright]{beamer@frametitleshade}{0.7\paperheight}{%
  color(50pt)=(titleleft);
  color(0.85\paperwidth)=(titleright)}

\defbeamertemplate*{frametitle}{horizontal shading}
{%
  \nointerlineskip%
  \vskip+3pt%
  \hbox{\leavevmode
    \advance\beamer@leftmargin by -12bp%
    \advance\beamer@rightmargin by -12bp%
    \beamer@tempdim=\textwidth%
    \advance\beamer@tempdim by \beamer@leftmargin%
    \advance\beamer@tempdim by \beamer@rightmargin%
    \hskip-\Gm@lmargin\hbox{%
      \setbox\beamer@tempbox=\hbox{\begin{minipage}[b]{\paperwidth}%
          \vbox{}\vskip-.75ex%
          \leftskip2.8cm%
          \rightskip0.3cm plus1fil\leavevmode
          \insertframetitle%
          \ifx\insertframesubtitle\@empty%
            \strut\par%
          \else
            \par{\usebeamerfont*{framesubtitle}{\usebeamercolor[fg]{framesubtitle}\insertframesubtitle}\strut\par}%
          \fi%
          \nointerlineskip
          \vbox{}%
          \end{minipage}}%
      \beamer@tempdim=\ht\beamer@tempbox%
      \advance\beamer@tempdim by 2pt%
      \begin{pgfpicture}{0pt}{0pt}{\paperwidth}{\beamer@tempdim}
        \usebeamercolor{frametitle right}
%        \pgfpathrectangle{\pgfpointorigin}{\pgfpoint{\paperwidth}{\beamer@tempdim}} 
         \pgfsetcornersarced{\pgfpoint{3mm}{3mm}}
         \pgfpathrectanglecorners{\pgfpoint{.2\paperwidth}{0}}{\pgfpoint{.8\paperwidth}{\beamer@tempdim}}
        \pgfusepath{clip}
        \pgftext[left,base]{\pgfuseshading{beamer@frametitleshade}}
      \end{pgfpicture}
      \hskip-\paperwidth%
      \box\beamer@tempbox%
    }%
    \hskip-\Gm@rmargin%
  }%
    \vskip-2pt
}
\makeatother

\setbeamerfont{frametitle}{size=\Large,series=\bfseries}

\begin{document}

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

\end{document}