使用方框标记 tikz 中的边缘

Question

我正在通过手动创建节点并将其放置在边缘中心来创建边缘标签。有没有更简洁的方法？另外，我希望边缘在标签内不可见。

\begin{figure}
\centering
{
    \begin{tikzpicture}[    transform shape]
        \newcommand\XA{-3}
        \newcommand\YA{0}
        \node (x) [circle, draw=black, align=center, minimum size=1cm] at (\XA,\YA) {$V$};
        \node (y) [circle, draw=black, align=center, minimum size=1cm   ] at (\XA-1.5,\YA-1.5) {$U$};
        \node (l1) [thin, draw=black, align=center, minimum width=0.5cm, minimum height=0.5cm] at(\XA-0.75,\YA-0.75) {\Large d};
        \path[every node/.style={font=\sffamily\small}]
        (x) edge[->] node {} (y);
    \end{tikzpicture}
}
\end{figure}

Answer 1

使用fill=white。

\documentclass{article}
\usepackage{tikz}
\begin{document}
  \begin{figure}
\centering
    \begin{tikzpicture}[transform shape,mylabel/.style={thin, draw=black, align=center, minimum width=0.5cm, minimum height=0.5cm,fill=white,font=\Large}]
        \newcommand\XA{-3}
        \newcommand\YA{0}
        \node (x) [circle, draw=black, align=center, minimum size=1cm] at (\XA,\YA) {$V$};
        \node (y) [circle, draw=black, align=center, minimum size=1cm   ] at (\XA-1.5,\YA-1.5) {$U$};
        \draw[->]  (x) -- node[mylabel] {d} (y);
    \end{tikzpicture}
\end{figure}
\end{document}

\centering不接受参数，因此{...}不需要。另外，edge它是一个怪物，不要用它来做小事。