制作依赖于后续环境的标题

Question

回答问题的新解决方案

您希望使用文档中稍后出现的信息为您的问题及其部分构建标题。显而易见的方法是使用\label和\ref，但由于您希望在后台执行此操作，因此需要动态生成标签名称。

用于交叉引用的动态标签

下面我定义了两个命令\dlabel和，\dref它们的功能分别类似于\label和\ref，不同之处在于它们使用动态名称作为标签，具体取决于计数器的当前值。语法为：

\dlabel{labelName}{counter}[value]
\dref{labelName}{counter}

这里的“计数器”是任何普通的乳胶计数器，“值”是存储用于交叉引用的内容（任何事物counter可以在此处存储 sensible 。如果未提供任何值，则标签的值默认为（其版本）的值\arabic。标签在辅助文件中存储为labelName-<counter value>。

如果你想使用返回的值，\dref你不能只使用\dref。相反，你需要使用一个特殊的计数器\theextractedReference（这类似于数学使用\pgfmathresult）。还有第三个宏，\Dref其语法与完全相同\dref，用于设置extractedReference计数器而不打印引用的值。

动态标签使用引用计数包以及一些扩展技巧。它们既可以工作，也可以不工作超链接并且应该对任何其他使用引用的包感到满意（我只检查了 hyperref）。

你的问题

一旦动态标签到位，做你想做的事情就不那么难了。你在你的问题中已经做了大部分工作。需要添加的只是在环境末尾使用添加动态标签的一些命令\dlabel，然后在环境开始时你需要使用构建标题\Dref。代码中还有一些注释。

以下是您的 MWE 的输出：

enter image description here

代码如下：

\documentclass{article}
\usepackage{xcolor}
\usepackage{ifthen}
\usepackage{amsmath,amsfonts,amsthm,amssymb}
\usepackage{etoolbox}
\usepackage{xparse}
\usepackage{refcount}

%% dynamic references based on counters
\makeatletter
%dynamic label: \dlabel{label name}{counter}[value]
\NewDocumentCommand\dlabel{mmo}{%
  \IfNoValueTF{#3}{\def\dlabelval{\value{#2}}}{\def\dlabelval{#3}}%
  \edef\mylabel{#1-\arabic{#2}}\edef\@currentlabel{\dlabelval}%
  \expandafter\label{\mylabel}%
}
% dynamic reference: \dref{label name}{counter}
\newcommand\dref[2]{
  \edef\myref{#1-\arabic{#2}}%
  \expandafter\ref{\myref}%
}
% dynamic reference: \Dref{label name}{counter}
%  - sets \theextractedReference equal to the reference value
\newcounter{extractedReference}
\newcommand\Dref[2]{%
  \edef\myref{#1-\arabic{#2}}%
  \expandafter\setcounterref{extractedReference}{\myref}%
}

%% problems
\setcounter{secnumdepth}{0}
\newcounter{problemNumber}% current problem number
\def\theproblemNumber{Problem~\arabic{problemNumber}}%
\newcounter{partNumber}% current part number
\def\thepartNumber{Part~\Alph{partNumber}}%
\newcounter{problemPoints}% points for problem: cumulative
\newcounter{partPoints}% points for part: cumulative

\newenvironment{problem}[1][]%
  {\stepcounter{problemNumber}% increment problem number
   \setcounter{problemPoints}{0}% reset points for problem
   \setcounter{partNumber}{0}% reset parts for problem
   % building the problem subheading: (# parts, # points)
   \Dref{problemParts}{problemNumber}% set \theextractedReference = #parts
   \let\problemHeading\relax% clear problem heading
   \ifnum\theextractedReference>0% add number of parts to heading
      \ifnum\theextractedReference=1%
        \def\problemHeading{1 part}%
      \else
        \xdef\problemHeading{\theextractedReference\space parts}%
      \fi
   \fi
   \Dref{problemPoints}{problemNumber}% set \theextractedReference = #points
   \ifnum\theextractedReference>0% add number of points to heading
      % add comma to heading as necessary
      \ifx\problemHeading\relax\relax\else\appto\problemHeading{, }\fi
      \ifnum\theextractedReference=1%
        \appto\problemHeading{1 point}%
      \else
        \xappto\problemHeading{\theextractedReference\space points}%
      \fi
   \fi
   \section{\theproblemNumber: #1% add header if not empty=\relax
            \ifx\problemHeading\relax\relax\else\space(\problemHeading)\fi}%
  }{% save number of parts and point for the problem
    \dlabel{problemParts}{problemNumber}[\arabic{partNumber}]
    \dlabel{problemPoints}{problemNumber}[\theproblemPoints]
  }

\renewenvironment{part}%
  {\stepcounter{partNumber}%
   \setcounter{partPoints}{0}
   \Dref{partPoints:\arabic{problemNumber}}{partNumber}% set \theextractedReference = #points %%% edited the partNumber counter
   \let\partHeading\relax% clear heading
   \ifnum\theextractedReference>0% add number of points to heading
      \ifnum\theextractedReference=1%
        \def\partHeading{1 point}%
      \else
        \def\partHeading{\theextractedReference\space points}%
      \fi
   \fi
   \subsection{\thepartNumber: % add header if not empty=\relax
               \ifx\partHeading\relax\relax\else Total \partHeading\fi}
   }{% save number of points for part
     \dlabel{partPoints:\arabic{problemNumber}}{partNumber}[\thepartPoints]}   %%% edited the partNumber counter

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% from OP
\newenvironment{question}[1][]{
    \ifthenelse{
        \equal{#1}{}
    }{}{% increment point counters for parts and problems
        \addtocounter{partPoints}{#1}
        \addtocounter{problemPoints}{#1}
        \ifthenelse{
            \equal{#1}{1}
        }{
            \noindent\textbf{(#1 point)}
        }{
            \noindent\textbf{(#1 points)}
        }}
    }{}

\newenvironment{solution}[1][]{%
    \begin{trivlist}%
    \def\@tempa{#1}%
    \ifx\@tempa\empty%
      \item[]%
    \else%
      \item[\hskip\labelsep\relax #1]%
    \fi%
    \textbf{solution}: \newline
  }{%
    \mbox{}\penalty10000\hfill\ensuremath{\Box} % \hmcpset@endmark%
    \end{trivlist}%
  }

\makeatother

\begin{document}

  \begin{problem}[First Title]
    \begin{part}
      \begin{question}[10]
      Q1
      \end{question}

      \begin{solution}
      Sol to Q1
      \end{solution}
    \end{part}

    \begin{part}
      \begin{question}[20]
      Q1
      \end{question}
    \end{part}

    \begin{part}
      \begin{question}[10]
      Q1
      \end{question}

      \begin{question}[10]
      Q2
      \end{question}
    \end{part}
  \end{problem}

  \begin{problem}[Second title]
    \begin{question}[20]
    Q2 (parts are not the essential component in every problem, when it
    does not include the part, count it as 1)
    \end{question}

    \begin{solution}
    \begin{align}
    step 1 \\
    step 2 \\
    e=mc^2
    \end{align}
    \end{solution}
  \end{problem}

\end{document}

顺便说一句，第二个问题不包含任何部分，所以我认为这里唯一合理的标题是打印可用的点数，而不提及部分数。这就是我的解决方案所做的。或者，您可以打印问题在问题中。

Answer 1