无法绘制与线平行的箭头

Question

我正在尝试绘制一个区域。我无法绘制与连接内部区域和外部区域的线平行的箭头。这是我所拥有的

这就是我想要的

我目前拥有的代码如下。提前致谢。

    \documentclass[tikz,border=3.14mm]{standalone}
    \usepackage{graphicx,wrapfig}
    \usetikzlibrary{calc,hobby} % To draw the smooth curve
     \begin{document}


    \begin{tikzpicture}

    \draw (0,1) to [closed,curve through={(2,3) (3.3,4) (3,6) (-1,6)(-1.4,5)(-3,3.8) }] (0,1);

    \draw [blue](1,5) to [closed,curve through={(1.3,5.6)(2,5.8)(2.4,5.2)(2.2,4.7) (1.4,4.6)}] (1,5); 
    \draw [red](-1.6,2.5) to [closed,curve through={(-1.5,2.7)(-0.5,3.3)(-0.1,2.7)(-0.3,2.2) (-0.9,1.9)}] (-1.6,2.5); 
    \draw[densely dashed] (101:2.15) -- (74:1.3);
    \draw[->] (101:1.75) -- (77:1);
    \end{tikzpicture}
    \end{document}

Answer 1

由于您已在加载calc，因此可以使用部分的方法13.5.4 距离修饰符的语法pgfmanual v3.1.5（以及部分13.5.3 部分修饰语的句法) 来定义距离虚线路径有一定距离的点。

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{calc,hobby} % To draw the smooth curve
 \begin{document}


\begin{tikzpicture}

\draw (0,1) to [closed,curve through={(2,3) (3.3,4) (3,6) (-1,6)(-1.4,5)(-3,3.8) }] (0,1);

\draw [blue](1,5) to [closed,curve through={(1.3,5.6)(2,5.8)(2.4,5.2)(2.2,4.7) (1.4,4.6)}] (1,5); 
\draw [red](-1.6,2.5) to [closed,curve through={(-1.5,2.7)(-0.5,3.3)(-0.1,2.7)(-0.3,2.2) (-0.9,1.9)}] (-1.6,2.5); 
\draw[densely dashed] (101:2.15) -- (74:1.3) coordinate [pos=0] (p0) 
coordinate [pos=1] (p1);
\draw[-stealth] ($ ($(p0)!0.2!(p1)$)!0.3cm!90:(p1) $) --  
($ ($(p0)!0.8!(p1)$)!0.3cm!90:(p1) $) ;
\end{tikzpicture}
\end{document}

但是，由于您似乎想要构建与这些曲线正交的线段，因此我建议采用另一种方法。

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{arrows.meta,bending,hobby,intersections,decorations.markings} % To draw the smooth curve
\tikzset{% 
    attach arrow/.style={
    decoration={
        markings,
         mark=at position 0 with {\pgfextra{%
         \pgfmathsetmacro{\tmpArrowTime}{\pgfkeysvalueof{/tikz/arc arrow/length}/(\pgfdecoratedpathlength)}%
         \xdef\tmpArrowTime{\tmpArrowTime}}},
        mark=at position {#1-3*\tmpArrowTime} with {\coordinate(@1);},
        mark=at position {#1-2*\tmpArrowTime} with {\coordinate(@2);},
        mark=at position {#1-1*\tmpArrowTime} with {\coordinate(@3);},
        mark=at position {#1+\tmpArrowTime/2} with {\coordinate(@4);
        \draw[-{Stealth[length=\pgfkeysvalueof{/tikz/arc arrow/length},bend]}] plot[smooth]
         coordinates {(@1) (@2) (@3) (@4)};},
        },
     postaction=decorate,
     },
     attach arrow/.default=0.5,
     arc arrow/.cd,length/.initial=2mm,
}


\begin{document}


\begin{tikzpicture}

\draw[name path=outer,attach arrow/.list={0.1,0.6,0.9}] (0,1) to [closed,curve through={(2,3) (3.3,4) (3,6) (-1,6)(-1.4,5)(-3,3.8) }] (0,1);
\def\BluePath{(1,5) to [closed,curve through={(1.3,5.6)(2,5.8)(2.4,5.2)(2.2,4.7) (1.4,4.6)}] (1,5)}
\draw[blue,attach arrow/.list={0.2,0.7}] \BluePath; 
\path[postaction={decorate,decoration={markings,
mark=at position 0.4 with {\path[overlay,name path=blue] (0,0) coordinate (b0) -- (0,2) coordinate (b1);}}}]
    \BluePath; 
\def\RedPath{(-1.6,2.5) to [closed,curve through={(-1.5,2.7)(-0.1,2.7)(-0.3,2.2) (-0.9,1.9)}] (-1.6,2.5)}   
\draw[red,attach arrow/.list={0.3,0.8}] \RedPath; 
\path[postaction={decorate,decoration={markings,
mark=at position 0.65 with {\path[overlay,name path=red] (0,0) coordinate (r0) -- (0,2) coordinate (r1);}}}]
    \RedPath; 
\draw[densely dashed,
    name intersections={of=blue and outer,by=b1},
    postaction={decorate,decoration={markings,
    mark={at position 0.5 with {
        \draw[-stealth,solid] (-0.2,0.2) -- (0.2,0.2);
        \draw[-stealth,solid] (0.2,-0.2) -- (-0.2,-0.2);}}}}] 
    (b0) -- (b1);
\draw[densely dashed,
    name intersections={of=red and outer,by=r1},
    postaction={decorate,decoration={markings,
    mark={at position 0.5 with {
        \draw[-stealth,solid] (-0.2,0.2) -- (0.2,0.2);
        \draw[-stealth,solid] (0.2,-0.2) -- (-0.2,-0.2);}}}}] 
    (r0) -- (r1);
\end{tikzpicture}
\end{document}