在 TikZ 中添加箭头

Question

如何添加这一行？

当前代码：

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{fp, tikz}
\usetikzlibrary{arrows,shapes,backgrounds,patterns,fadings,matrix,arrows,calc,
    intersections,decorations.markings,
    positioning,external,arrows.meta}
\tikzset{
    block/.style = {draw, rectangle,
        minimum height=1cm,
        minimum width=2cm},
    input/.style = {coordinate,node distance=1cm},
    output/.style = {coordinate,node distance=6cm},
    arrow/.style={draw, -latex,node distance=2cm},
    pinstyle/.style = {pin edge={latex-, black,node distance=2cm}},
    sum/.style = {draw, circle, node distance=1cm},
}
\begin{document}


   \begin{tikzpicture}[auto, >=latex', transform shape,font={\sffamily \small}] 

    \node [draw=black,
    minimum width=1.6cm,
    minimum height=1.2cm, 
    align=center]   (1) {1};
    
    \node [draw=black,
    minimum width=1.6cm,
    minimum height=1.2cm, 
    align=center,
    right=0.6cm of 1]   (2) {2};
    
    \node [draw=black,
    minimum width=1.6cm,
    minimum height=1.2cm, 
    align=center,
    right=0.6cm of 2]   (3) {3}; 

    \draw[->,line width=0.25mm] (1.east) -- (2.west);
    \draw[->,line width=0.25mm] (2.east) -- (3.west);
    
    \end{tikzpicture}
\end{document}

Answer 1

由于您加载了计算库，您可以使用它的功能来查找两个节点之间的中点。您可以在代码后添加以下行。

\draw[->,line width=0.25mm] ($(1)!0.5!(2)$) --++ (0,1.3cm) -| (3.north);

第一个坐标（$(1)!0.5!(2)$）评估节点 (1) 和 (2) 之间的中点。

第二个坐标 --++ (0,1.3cm) 是我创建的虚拟点，用于将箭头抬高到节点上方。您可以根据需要调整 1.3cm。

Answer 2

(1)您可以在从到的线段上设置一个坐标，(2)就像一个节点一样。线的中点是默认值。然后您可以从那里绘制新箭头。

另外，我还大大简化了你的代码。

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{positioning, arrows}

\tikzset{
    block/.style = {draw, rectangle, minimum height=1.2cm, minimum width=1.6cm}
}

\begin{document}

   \begin{tikzpicture}[>=latex',font={\sffamily\small}, node distance=.6cm] 

    \node [block] (1) {1};
    \node [block, right=of 1] (2) {2};
    \node [block, right=of 2] (3) {3}; 

    \draw[->,line width=0.25mm] (1.east) --coordinate(M) (2.west);
    \draw[->,line width=0.25mm] (2.east) -- (3.west);
    \draw[->,line width=0.25mm] (M) --++ (0,1) -| (3);
    
    \end{tikzpicture}
    
\end{document}

Answer 3

通过使用该ext.paths.ortho库，真正的 MWE（最小工作示例）专注于您的问题：

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                chains,
                ext.paths.ortho,    % defined in the tikz-ext package
                positioning,
                }

\begin{document}
    \begin{tikzpicture}[
node distance = 4mm and 6mm,
  start chain = going right,
   arr/.style = {-{Straight Barb[scale=0.8]}, semithick},
   box/.style = {% default is rectangle
                 draw, minimum height = 10mm, minimum width=20mm,
                 on chain, join=by arr}
                        ]
\foreach \i in {1,2,3}
    \node [box] (n\i) {\i};
%
\path       (n1) -- coordinate  (aux) (n2);
\draw[arr]  (aux) r-ud (n3.north);
    \end{tikzpicture}
\end{document}

Answer 4

像这样：

代码（不使用任何库）：

\documentclass{article}
\usepackage{tikz}

\begin{document}
    \begin{tikzpicture}
         \draw[line width=3pt] (0,0) node[minimum height=2cm,minimum width=3cm,draw] (1) {\Huge \bfseries 1};
        \draw[line width=3pt] (5,0) node[minimum height=2cm,minimum width=3cm,draw] (2) {\Huge \bfseries 2};
        \draw[line width=3pt] (10,0) node[minimum height=2cm,minimum width=3cm,draw] (3) {\Huge \bfseries 3};       
        \draw[-latex,line width=3pt] (1)  -- (2);
        \draw[-latex,line width=3pt] (2) -- (3);
        \draw[-latex,line width=3pt] (2.5,0)--(2.5,2)--(10,2)--(3);     
    \end{tikzpicture}
\end{document}