标记旁边的标签

Question

\documentclass[tikz, border=1cm]{standalone}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{decorations.markings}
\begin{document}
\tikzset{%
  tensionarrowreversed/.tip={%
    Triangle[length=2.5mm, width=2.5mm, open, reversed]
  },
  %
  %
  tensionarrow/.tip={%
    Triangle[length=2.5mm, width=2.5mm, open]
  },
  %
  %
  string/.style={%
    draw, color=blue,
    decoration={markings,
                mark= at position 0.75 with {\arrow{tensionarrowreversed}}},
                postaction={decorate},
    decoration={markings,
                mark= at position 0.25 with {\arrow{tensionarrow}}},
                postaction={decorate}
  },
  %
 }
\begin{tikzpicture}
\draw[string] (0, 0)--(0, 5);
\end{tikzpicture}
\end{document}

在上面的代码中，如何定位标记并在其旁边放置标签？（图像中的标签是手工放置的。）

Answer 1

您可以使用pos关键字将节点定位在路径上某段距离的一小部分处。

reversed还要注意，箭头尖端规范中的 和 使用之间存在差异\arrowreversed。前者将后端放置在指定位置，后者将尖端放置在指定位置，如下所示。

\documentclass[tikz, border=1cm]{standalone}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{decorations.markings}
\begin{document}
\tikzset{%
  tensionarrowreversed/.tip={%
    Triangle[length=2.5mm, width=2.5mm, open, reversed, red] % note added red
  },
  %
  %
  tensionarrow/.tip={%
    Triangle[length=2.5mm, width=2.5mm, open]
  },
  %
  %
  string/.style={%
    draw, color=blue,
    decoration={markings, % you can have multiple arrow tips in one decoration
                mark=at position 0.25 with {\arrow{tensionarrow}},
                mark=at position 0.75 with {\arrowreversed{tensionarrow}}, % added this
                mark=at position 0.75 with {\arrow{tensionarrowreversed}}}, % same position as previous, but different arrow tip
                postaction={decorate},
  },
  %
 }
\begin{tikzpicture}
\draw[string] (0, 0)--(0, 5) node[right,pos=0.25] {Text} node[right,pos=0.75] {txeT};
\end{tikzpicture}
\end{document}