TikZ：如何在形状（或路径）上使用内外线宽

Question 1

您可以应用preaction较粗的线条或postaction较细的线条：

\documentclass[margin=5mm, varwidth]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes}
\begin{document}

\begin{tikzpicture}[]
\node[rounded rectangle, draw=pink, line width=5mm,
minimum width=50mm, minimum height=20mm, preaction={draw=red, line width=6mm},
](s){*};
\end{tikzpicture}
\end{document}

Answer

您可以应用preaction较粗的线条或postaction较细的线条：

\documentclass[margin=5mm, varwidth]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes}
\begin{document}

\begin{tikzpicture}[]
\node[rounded rectangle, draw=pink, line width=5mm,
minimum width=50mm, minimum height=20mm, preaction={draw=red, line width=6mm},
](s){*};
\end{tikzpicture}
\end{document}

Question 2

如果您对内线和外线具有相同的样式感到满意，则可以使用以下线条double：

\documentclass[margin=5mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes}

\begin{document}
\begin{tikzpicture}

\node[
    rounded rectangle, 
    minimum width=50mm, 
    minimum height=20mm, 
    draw=black, 
    line width=0.5mm, 
    double=pink,
    double distance=5mm
] (s) {*};

\end{tikzpicture}
\end{document}

Answer

如果您对内线和外线具有相同的样式感到满意，则可以使用以下线条double：

\documentclass[margin=5mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes}

\begin{document}
\begin{tikzpicture}

\node[
    rounded rectangle, 
    minimum width=50mm, 
    minimum height=20mm, 
    draw=black, 
    line width=0.5mm, 
    double=pink,
    double distance=5mm
] (s) {*};

\end{tikzpicture}
\end{document}

Question 3

前三个示例（手册中的示例之后）展示了如何使用 TikZ 执行与 PGFpicture 完全相同的操作。TikZ 不提供直接接口，\pgfsetinnerlinewidth但也会调整外（见下文）使用double distance或之一时的线宽。不过，我添加了一个直接界面，需要用户自行调整。double distance between line centers\pgfsetinnerlinewidthline width

当你使用double（或\pgfsetinnerlinewidth）PGF/TikZ 绘制两次路径时，首先使用“外”线宽/颜色，然后使用内线宽/颜色。

这意味着内线宽需要小于外线宽以double产生视觉效果（除非不透明度发挥作用）。

这可能也是 TikZ 确保 PGF 线宽（成为外线宽）进行调整，以便double distance将double distance between line centers 线宽（由用户指定）添加到内行宽

在“两侧”内线宽与double distance和
这样它就覆盖了给定的宽度double distance between line centers（我希望我最后的 TikZpicture 比我的文字更清晰）。

因为你想要

[…] 有一个内线（粉色，5mm）和上下两条外线（黑色，非常细）。

你需要

double distance = 5mm

和

line width = <very thin>

并且 PGF/TikZ 将用绘制黑线，line width = 5mm + 2 × <very thin>但随后直接覆盖一条带子，5mm留下黑色条纹<very thin>。

我使用了ultra thin（0.1pt），但你当然可以调整它。

代码

\documentclass[margin=5mm, tikz]{standalone}
\usetikzlibrary{shapes.misc}
\makeatletter
\tikzset{inner line width/.code=%
  \tikzset{double}\pgfmathsetlength\pgf@x{#1}%
  \edef\tikz@double@setup{\noexpand\pgfsetinnerlinewidth{\the\pgf@x}}}
\makeatother
\begin{document}
\begin{tikzpicture}
\pgfpathmoveto{\pgfpointorigin}
\pgfpathlineto{\pgfpoint{1cm}{1cm}}
\pgfpathlineto{\pgfpoint{1cm}{0cm}}
\pgfsetlinewidth{2pt}
\pgfsetinnerlinewidth{1pt}
\pgfsetinnerstrokecolor{red!50}
\pgfusepath{stroke}
\end{tikzpicture}

\tikz
  \draw[
    line width = .5pt,     % \pgfsetlinewidth{.5pt}
    double distance = 1pt, % \pgfsetinnerlinewidth{1pt}
                       % and \pgfsetlinewidth     {1pt + 2 * \pgflinewidth}
    double=red!50          % \pgfsetinnerstrokecolor{red!50}
  ]   (0pt, 0pt)           % \pgfpathmoveto{\pgfpointorigin}
   -- (1cm, 1cm)           % \pgfpathlineto{\pgfpoint{1cm}{1cm}}
   -- (1cm, 0cm)           % \pgfpathlineto{\pgfpoint{1cm}{0cm}}
   ;                       % \pgfusepath{stroke}
\tikz
  \draw[
    line width = .5pt,     % \pgfsetlinewidth{.5pt}
    double distance between line centers = 1.5pt,
                           % \pgfsetinnerlinewidth{\pgflinewidth - 1.5pt}
                       % and \pgfsetlinewidth     {\pgflinewidth + 1.5pt}
    double = red!50        % \pgfsetinnerstrokecolor{red!50}
  ] (0pt, 0pt) -- (1cm, 1cm) -- (1cm, 0cm);

\tikz
  \draw[line width=2pt, inner line width=1pt, double=red!50]
    (0pt, 0pt) -- (1cm, 1cm) -- (1cm, 0cm);

\tikz
  \node[rounded rectangle, draw, double=pink, double distance=5mm, ultra thin,
       minimum width=50mm, minimum height=20mm](s){*};
       
\begin{tikzpicture}
\draw[step=5mm] (-.25,-.25) grid (3.25,2.8);

\tikzset{double=red, nodes={white, align=center, scale=.4}}\ttfamily
\draw[double distance=5mm,                      line width=2mm]  (0,0.25) -- node{dd = 5mm,    lw = 2mm\\→ ilw = 5mm, olw = 5 + 2×2mm} + (right:3);
\draw[double distance between line centers=5mm, line width=2mm]  (0,1.25) -- node{ddblc = 5mm, lw = 2mm\\→ ilw = 5mm - 2mm, olw = 5mm + 2mm} + (right:3);
\draw[inner line width=5mm,                     line width=10mm] (0,2.25) -- node{ilw = 5mm,   lw = 10mm\\→ ilw = 5mm, olw = 10mm}     + (right:3);
\end{tikzpicture}
\end{document}

输出

Answer