Continuing solution frame for exams

Question

New edit: The proposed answer by magula, which used to work with version 2.5 of exam.cls no longer works with the current version 2.603. The following was included as a note for version 2.601: "We changed command and environment names in the code from framed.sty that's included (slightly modified) in exam.cls so that the user can say \usepackage{framed} without creating conflicts. This also allows the user to use packages, such as minted.sty, that load framed.sty." I'm not sure if the changes made now render the current given answer/hack useless, but it simply deosn't work anymore.

Question: Can TheSolution environment be renewed in such a way that the framed box provided for the solution does not break into separate boxes on different pages as also illustrated in this question.

The code

\documentclass[answers]{exam}
\usepackage{lipsum}
\usepackage{mdframed}

\def\MakeFramed#1{\begin{mdframed}}
\def\endMakeFramed{\end{mdframed}}

\begin{document}

\begin{questions}

\question A short question.
\begin{solution}
A short solution.
\end{solution}

\question A question with a long solution.

\begin{solution}
The long solution continues onto another page: \lipsum[1-8]
\end{solution}

\end{questions}
\end{document}

produces a page break that looks like

instead of the following desired look:

In the manual, on page 74, it mentions that one could use \renewenvironment to completely customize the solution environment by changing the definition of TheSolution. My question is how I could do this to make the frame extend onto the next page in the desired way indicated above and the linked to question at the beginning of this question.

Answer 1

With the new version, the commands you need to change to remimplement the original solution are exam@MakeFramed and endexam@MakeFramed

So you should change

\def\MakeFramed#1{\begin{mdframed}}
\def\endMakeFramed{\end{mdframed}}

to

\makeatletter
\def\exam@MakeFramed#1{\begin{mdframed}}
\def\endexam@MakeFramed{\end{mdframed}}
\makeatother

This is a classic example of namespacing in TeX, where private macros have their name prefixed with the name of the package they belong to.

Answer 2

Just redefining TheSolution environment to be mdframed seems to work. You can add the heading "Solution:" and provide extra vertical spacing to match the original style too:

with page breaks like

\documentclass[answers]{exam}
\usepackage{lipsum}
\usepackage{mdframed}

\renewenvironment{TheSolution}{\begin{mdframed}[skipabove=\baselineskip,innertopmargin=\baselineskip,innerbottommargin=\baselineskip]
  \textbf{Solution:}\enspace\ignorespaces}{\end{mdframed}}

\begin{document}

\begin{questions}

\question A short question.
\begin{solution}
A short solution.
\end{solution}

\question A question with a long solution.

\begin{solution}
The long solution continues onto another page: \lipsum[1-8]
\end{solution}

\end{questions}
\end{document}

Answer 3

\usepackage{mdframed}

\def\MakeFramed#1{\begin{mdframed}}
\def\endMakeFramed{\end{mdframed}}

This simply replaces the commands TheSolution uses at start and end of the content with the mdframed ones.