如何在 Latex 中制作一棵树？

Question

我们怎样才能将 A 移至中心？

\documentclass[border=10pt]{standalone}
\usepackage[edges]{forest}
\usepackage[T1]{fontenc}
\tikzset{%
  parent/.style={align=center,text width=3cm,rounded corners=3pt},
  child/.style={align=center,text width=3cm,rounded corners=3pt}
}
\begin{document}
\begin{forest}
  for tree={
    % edge+={->},% uncomment for arrows
    draw,
    rounded corners,
    node options={align=center,},
    text width=2.7cm,
  },
  where level=0{%
    parent anchor=children,
  }{%
    folder,
    grow'=0,
    if level=1{% this changes the edges from level 0 to nodes at level 1
      before typesetting nodes={child anchor=north},
      edge path'={(!u.parent anchor) -- ++(0,-5pt) -| (.child anchor)},
    }{},
  }
  [A, fill=gray!25, parent
  [B, for tree={fill=brown!25, child}
  ]
  [C, for tree={fill=blue!25, child}
  ]
  ]
  ]
\end{forest}
\end{document}

Answer 1

您的代码对于这棵简单的树来说没有必要那么复杂。

\documentclass[border=10pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage[edges]{forest}
\usetikzlibrary{arrows.meta}

\begin{document}
\begin{forest}
  for tree={
% nodes
    draw,
    rounded corners,
    fill=gray!25,
    text width=3 cm,
    text centered,
% tree
    grow=270,
    parent anchor=south,
    child anchor=north,
%    edge = {-Straight Barb},
forked edge,
    l sep=8mm,
 fork sep=4mm,
    s sep=2mm
        }
[A
  [B, fill=brown!25]
  [C, fill=blue!25]
]
\end{forest}
\end{document}