使用pgfkeys，我想像使用对象构造函数设置属性一样初始化键。
这样我就可以根据的一些初始属性来创建键等/Photo/May，并设置一些默认值。/Photo/June/Photo
显然这应该很容易，但我似乎没有正确解释手册：
! Package pgfkeys Error: I do not know the key '/Photo/May/defaults' and I am going to ignore it. Perhaps you misspelled it.
梅威瑟：
\documentclass{article}
\makeatletter
\usepackage{pgfkeys}
\pgfkeys{
/Photo/.is family, /Photo,
init/.style = {
defaults/.style = {file = {}, bleed = 0pt},
file/.initial = {},
bleed/.initial = {},
}
}
% #1 = options, #2 = photo name
\newcommand\SetPhoto[2][]{%
\pgfkeys{%
/Photo/#2/.is family, /Photo/#2,
/Photo/#2/.append style=/Photo/init,
defaults, file={#2},
#1%
}%
}
\newcommand\DoPhoto[1]{%
% suppose it was an image...
\hskip -\pgfkeysvalueof{/Photo/#1/bleed}%
\frame{\pgfkeysvalueof{/Photo/#1/file}}%
}
\setlength{\parskip}{0pt}%
\setlength{\parindent}{0pt}%
\makeatother
\begin{document}
% somewhere early in the document
\SetPhoto{May}%
\SetPhoto[bleed=3mm]{June}%
\SetPhoto[bleed=5mm]{July}%
% typeset the photos with the given options
\DoPhoto{May}
\DoPhoto{June}
\DoPhoto{July}
\end{document}
答案1
明白了！你不需要.append style=/Photo/init，你只需要调用/Photo/init来应用其中设置的样式。
% #1 = options, #2 = photo name
\newcommand\SetPhoto[2][]{%
\pgfkeys{%
/Photo/#2/.is family, /Photo/#2,
/Photo/init,
defaults, file={#2},
#1%
}%
}
因此正确的 mwe 是：
\documentclass{article}
\makeatletter
\usepackage{pgfkeys}
\pgfkeys{
/Photo/.is family, /Photo,
init/.style = {
defaults/.style = {file = {}, bleed = 0pt},
file/.initial = {},
bleed/.initial = {},
}
}
% #1 = options, #2 = photo name
\newcommand\SetPhoto[2][]{%
\pgfkeys{%
/Photo/#2/.is family, /Photo/#2,
/Photo/init,
defaults, file={#2},
#1%
}%
}
\newcommand\DoPhoto[1]{%
% suppose it was an image...
\hskip -\pgfkeysvalueof{/Photo/#1/bleed}%
\frame{\pgfkeysvalueof{/Photo/#1/file}}%
}
\setlength{\parskip}{0pt}%
\setlength{\parindent}{0pt}%
\makeatother
\begin{document}
% somewhere early in the document
\SetPhoto{May}%
\SetPhoto[bleed=3mm]{June}%
\SetPhoto[bleed=5mm]{July}%
% typeset the photos with the given options
\DoPhoto{May}
\DoPhoto{June}
\DoPhoto{July}
\end{document}