如何沿着圆圈书写文字？

Question

使用 TikZ，我想沿着圆圈写一段文字，如示例所示：正方向。

Answer 1

您可以使用该decorations.text库：

\documentclass[11pt]{article}
\usepackage{tikz}
\usetikzlibrary{decorations.text}

\begin{document}

\begin{tikzpicture}
\draw[-latex,blue,postaction={decorate},decoration={text along path,
text={Positive direction},text align=center}]
(4,0) arc [start angle=-60,end angle=80,radius=4];
\end{tikzpicture}

\end{document}

如果您希望文本位于路径的中间（尽管这会降低可读性）：

\documentclass[11pt]{article}
\usepackage{tikz}
\usetikzlibrary{decorations.text}

\begin{document}

\begin{tikzpicture}
\path[decorate,decoration={text along path,
text={Positive direction},text align=center}]
(4,0) arc [start angle=-60,end angle=80,radius=4];
\draw[-latex,blue]
(4cm,0.8ex) arc [start angle=-60,end angle=80,radius=4cm-0.8ex];
\end{tikzpicture}

\end{document}

Answer 2

如果文本要位于路径上方，则text effects along path装饰允许为每个字符填充背景：

\documentclass[tikz,border=5]{standalone}
\usetikzlibrary{decorations.text}
\begin{document}
\tikz\path[draw=blue, -stealth,
  postaction={decorate,decoration={text effects along path,
    text={\ Positive direction\ }, text align=center,
    text effects/.cd, 
      text along path, 
      every character/.style={fill=white, yshift=-0.5ex}}}]
  (4, 0) arc [start angle=-60, end angle=80, radius=4];
\end{document}