Forest 中 z 级别的正确语法

Question

看完之后TikZ 中的“Z 级别”我尝试在我的森林图中实现 z 层，但没有成功：

\documentclass{standalone}
\usepackage{forest}
\usetikzlibrary{backgrounds}

\tikzset{zlevel/.style={%
    execute at begin scope={\pgfonlayer{#1}},
    execute at end scope={\endpgfonlayer}
}}

\begin{document}

\begin{forest} 
for tree={
    draw=black, align=center, l sep=4ex, parent anchor=south, child anchor=north,
    node options={font=\footnotesize, minimum width=14em, minimum height=10ex, rounded corners=1ex},
    edge path={
        \noexpand\path[\forestoption{edge}]
        (!u.parent anchor) -- +(0,-2ex) -| (.child anchor)\forestoption{edge label};
    }
}
[Parent,name=Parent
    [SubParent,name=SubParent
        [Child1,name=Child1
            [Child11]
            [Child12,name=Child12]
        ]
        [Child2
            [Child21]
            [Child22,name=Child22,node options={dashed}]
            [Child23,name=Child23]
        ]
        [Child3
            [Child31,name=Child31]
            [Child32]
        ]
    ]
]
%
\tikzset{every node/.style={font=\footnotesize, draw=green, minimum width=14em, minimum height=10ex, rounded corners=1ex}}
%
\begin{scope}[zlevel=1]
\draw[->,dashed] (Child22) to (SubParent);
\draw[->,dashed] (Child31) to[out=north east,in=south east] (SubParent);
\end{scope}
\end{forest}
\end{document}

目标是在它们穿过的森林节点后面绘制虚线箭头。要实现这一点需要进行哪些更改？

Answer 1

将内容放入背景的最简单方法是使用图层，background而不是定义其他图层。如果您需要更复杂的分层，则需要使用\pgfdeclarelayer和，\pgfsetlayers如您链接的答案中所述。background但是，对于图层，这在您加载库时已经完成backgrounds。

为了演示效果，我在节点中添加了 75% 不透明度的淡蓝色填充，以便背景线可以显示在树的前层：

\documentclass{standalone}
\usepackage{forest}
\usetikzlibrary{backgrounds}

\begin{document}

\begin{forest}
for tree={
    draw=black, align=center, l sep=4ex, parent anchor=south, child anchor=north,
    node options={font=\footnotesize, minimum width=14em, minimum height=10ex, rounded corners=1ex},
    edge path={
        \noexpand\path[\forestoption{edge}]
        (!u.parent anchor) -- +(0,-2ex) -| (.child anchor)\forestoption{edge label};
    },
    fill=blue!25,
    fill opacity=.75,
}
[Parent,name=Parent
    [SubParent,name=SubParent
        [Child1,name=Child1
            [Child11]
            [Child12,name=Child12]
        ]
        [Child2
            [Child21]
            [Child22,name=Child22,node options={dashed}]
            [Child23,name=Child23]
        ]
        [Child3
            [Child31,name=Child31]
            [Child32]
        ]
    ]
]
%
\tikzset{every node/.style={font=\footnotesize, draw=green, minimum width=14em, minimum height=10ex, rounded corners=1ex}}
%
\begin{scope}[on background layer]
\draw[->,dashed] (Child22) to (SubParent);
\draw[->,dashed] (Child31) to[out=north east,in=south east] (SubParent);
\end{scope}
\end{forest}
\end{document}