如何使用 tikz 连接图表中的线条？

Question

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shadows,positioning,shapes,arrows,decorations.markings,arrows.meta}

\tikzset{
      box/.style={draw,fill=white,rectangle,minimum size=2.5cm,align=center},
      diatostealth/.style={draw,{Diamond}-{Stealth}}
}

\begin{document}
\begin{tikzpicture}

\node[box](a){a}; 
\node[box, below left=1.5cm of a](b){b}; 
\node[box, below right=1.5cm of a](c){c}; 


% the arrows
\path[diatostealth] (a.south) -- (b.north){};
\path[diatostealth] (a.south) -- (c.north){};

\end{tikzpicture}
\end{document}

这就是我目前所拥有的。

这就是我想要实现的。

Answer 1

您可以使用中间坐标。因此，左侧的线可以通过以下方式实现：

\path[diatostealth, thick] 
    (a.south) 
    -- ++(0,-0.5cm)
    -| (b.north)
    ;

方法：

• 開始於(a.south)。
• 表示最后一个点下方的++坐标，-0.5cm
• 该-|方法先画一条水平线，然后再画一条垂直线到该点(b.north)。

代码：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shadows,positioning,shapes,arrows,decorations.markings,arrows.meta}

\tikzset{
      box/.style={draw,fill=white,rectangle,minimum size=2.5cm,align=center},
      diatostealth/.style={draw,{Diamond}-{Stealth}}
}

\begin{document}
\begin{tikzpicture}

\node[box](a){a}; 
\node[box, below left=1.5cm of a](b){b}; 
\node[box, below right=1.5cm of a](c){c}; 


% the arrows
\path[diatostealth, thick] 
    (a.south) 
    -- ++(0,-0.5cm)
    -| (b.north)
    ;
\path[diatostealth, thick] 
    (a.south) 
    -- ++(0,-0.5cm)
    -| (c.north){};

\end{tikzpicture}
\end{document}

Answer 2

如果它看起来像一棵树，那它应该是一棵forest……

\documentclass[tikz,border=12pt,mult,varwidth]{standalone}
\usepackage{forest,amssymb}
\usetikzlibrary{shadows,arrows.meta}

\begin{document}

\tikzset{
  my shadow/.style={drop shadow={shadow xshift=.25ex, shadow yshift=-.25ex}}
}

\begin{forest}
  for tree={
    draw,
    parent anchor=south,
    child anchor=north,
    fill=white,
    my shadow,
    minimum width=20pt,
    text height=7.5pt,
    font=\sffamily,
    edge path={
      \noexpand\path [-{Stealth[]}, \forestoption{edge}] (!u.parent anchor) node [inner sep=0pt, anchor=north, outer sep=0pt, scale=.5] {$\blacklozenge$} -- +(0,-5pt) -| (.child anchor)\forestoption{edge label};
    },
  }
  [a
    [b]
    [c]
  ]
\end{forest}