框架标题中的垂直颜色渐变（投影机）

Question

我想在 beamer 包中的 frametitle 元素的背景中创建一个垂直颜色渐变。我已成功为整个框架背景执行此操作（使用%\setbeamertemplate{background canvas} [vertical shading][bottom=blue!15,top=green,midpoint=.1]）。frametitles 的背景是否有类似的东西？谢谢！

\documentclass{beamer}
\usetheme[height=1cm]{rochester}
\setbeamertemplate{frametitle}[default][center]

\title{Presentation}
\subtitle{}
\author{}
\institute{}
\date{\today} 

\begin{document}

\begin{frame}
    \titlepage{}
\end{frame}

\begin{frame}
    \frametitle{Frametitle which should have vertical shading}
\end{frame}

\end{document}

Answer 1

\documentclass{beamer}
\usetheme[height=0cm]{Rochester}

\setbeamercolor{frametitle}{parent=subsection in head/foot}
\setbeamercolor{frametitle right}{bg=green}

\makeatletter
\pgfdeclareverticalshading[frametitle.bg,frametitle right.bg]{beamer@frametitleshade}{\paperwidth}{%
    color(0pt)=(frametitle right.bg);
    color(.15\paperheight)=(frametitle.bg)}

\AtBeginDocument{
    \pgfdeclareverticalshading{beamer@topshade}{\paperwidth}{%
        color(0pt)=(bg);
        color(4pt)=(black!50!bg)}
}

\setbeamertemplate{frametitle}
{%
    \nointerlineskip%
    \vskip-2pt%
    \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][.15\paperheight][c]{\paperwidth}%
                    \vbox{}\vskip-.75ex%
                    \leftskip0.3cm%
                    \rightskip0.3cm plus1fil\leavevmode
                    \hfill\insertframetitle\hfill%
                    \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%
        }%
        \nointerlineskip
        \vskip-0.2pt
        \hbox to\textwidth{\hskip-\Gm@lmargin\pgfuseshading{beamer@topshade}\hskip-\Gm@rmargin}
        \vskip-2pt
    }
\makeatother


\title{Presentation}
\subtitle{}
\author{}
\institute{}
\date{\today} 

\begin{document}

\begin{frame}
    \titlepage{}
\end{frame}

\section{text}
\subsection{wl}
\begin{frame}
    \frametitle{Frametitle which should have vertical shading}
\end{frame}

\end{document}