10 更改 tikz-qtrees 中 level distance 的计算方式 6天08时04分18秒

没研究过tikz-qtree这个包，只测试了下原生的写法。或许有更好的实践。晚点再测试下。

\documentclass[tikz,border=2pt]{standalone}
% \usepackage{tikz-qtree}
\begin{document}
\begin{tikzpicture}[grow=right,
                    growth parent anchor=east,
                    every node/.style={draw,
                                       inner sep=0pt, 
                                       outer sep=0pt},
                    level 1/.style={anchor=west,
                                    level distance=2cm,
                                    sibling distance=2cm},
                    level 2/.style={anchor=west,
                                    level distance=2cm,
                                    sibling distance=1cm},
                    edge from parent path={(\tikzparentnode.east) |- 
                                           (\tikzchildnode.west)}
]
    \node [anchor=east] {Root}
        child {node {A}
            child {node {a1}}
            child {node {a2}}}
        child {node {BBBB}
            child {node {b1}}
            child {node {b2}}};
    \draw [step=1cm,help lines] (0,-2) grid (6,2);
\end{tikzpicture}
\end{document}