透明度组和装饰标记

Question

我如何设置透明度以便箭头transparency group与路径属于同一类别？

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\begin{document}
\begin{tikzpicture}
  \tikzset{%
    > = stealth,
    arrow over path/.style = {%
      decoration = {%
        markings,
        mark = at position .5 with {\arrow {>};}
      },
      postaction = decorate
    }
  }
  \draw[arrow over path, semitransparent] (0,0) -- (1,1);
\end{tikzpicture}
\end{document}

Answer 1

根据要求，该评论变为答案：

据我所知，目前无法在路径内完成此操作。但是，transparency group可以使用（前提是后端驱动程序支持它）。请注意，透明度是在周围的scope 不是路径：

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\begin{document}
\begin{tikzpicture}
\tikzset{%
    > = stealth,
        arrow over path/.style = {%
        decoration = {%
        markings,
        mark = at position .5 with {\arrow {>};}
        },
        postaction = decorate
    }
}
\begin{scope}[opacity=.5, transparency group]
    \draw [arrow over path] (0,0) -- (1,1);
\end{scope}
\end{tikzpicture}
\end{document}