当我使用 tcolorbox 时，单列摘要会移至下一页

Question

问题似乎是，tcolorbox放置在单列环境中的，又嵌入在双列上下文中，仍然表现得像在双列环境中一样。因此，您需要准确地告诉它在哪里中断。您可以使用选项来执行此操作，break at并明确说明第一页上的框的大小。

例如，break at=15cm/0pt意味着可破坏框的第一部分（即标题后面的部分）的尺寸应为 15 厘米（这似乎是标题下方空间的大小），后面的框应尽可能大。（您的代码中已经有类似的东西了。）

遗憾的是，如果您决定将标题弄大一些（通过添加更多行），则需要调整这个明确的陈述。

以下方法似乎有效（尽管似乎存在较小的对齐问题）：

\documentclass[twocolumn]{article}
\usepackage{geometry,graphicx,xcolor,enumitem,amsmath,caption}

\definecolor{Cgreen}{RGB}{41,106,48}%LIGHT
\usepackage[most]{tcolorbox}

\begin{filecontents}{long2.sty}
%%
%% This is file `long2.sty'.
%%
%% Author: Tomas "tohecz" Hejda <[email protected]>
%%
%% Licenced under LaTeX-Project Public License version 1.3 or newer.
%% 
\NeedsTeXFormat{LaTeX2e}[1995/06/01]
\ProvidesPackage{long2}[2012/08/19 v0.1 long2: breakable one-column preamble in a two-column document]

\newlength\longtwo@top
\newlength\longtwo@bottom

\newsavebox\longtwo@box
\def\longtwo@repeat{%
    \longtwo@column[{\@twocolumnfalse
    \ifdim\ht\longtwo@box>1.00\textheight%1
      \begingroup
      \vbadness10000
      \setbox0\vsplit\longtwo@box to 1.00\textheight%1
      \setbox1\vbox{\unvbox\longtwo@box}
      \global\setbox\longtwo@box\vbox{\unvbox1}
      \setbox2\vbox to \textheight{%
        \unvbox0
      }
      \ht2=0.9\textheight
      \box2
      \endgroup
    \else
      \ifdim\ht\longtwo@box>0.84\textheight
        \global\let\longtwo@repeat\clearpage
      \else
        \global\let\longtwo@repeat\relax
      \fi
      \unvbox\longtwo@box
      \vspace{15pt plus 15pt}
    \fi
    }]%
  \longtwo@repeat
}

\long\def\longtwo@[#1]{%
  \begingroup
    \let\longtwo@column\twocolumn
    \let\longtwo@mkttl\maketitle
    \def\maketitle{
      \begingroup
      \let\newpage\relax
      \longtwo@mkttl
      \endgroup
    }
    \longtwo@column[{\@twocolumnfalse
    \global\setbox\longtwo@box\vbox{#1}%
    \ifdim\ht\longtwo@box>\textheight
      \begingroup
      \vbadness10000
      \setbox0\vsplit\longtwo@box to 1.00\textheight%1
      \setbox1\vbox{\unvbox\longtwo@box}%
      \global\setbox\longtwo@box\vbox{\unvbox1}%
      \setbox2\vbox to \textheight{%
        \unvbox0
      }
      \ht2=0.9\textheight
      \box2
      \endgroup
    \else
      \ifdim\ht\longtwo@box>0.87\textheight
        \global\let\longtwo@repeat\clearpage
      \else
        \global\let\longtwo@repeat\relax
      \fi
      \unvbox\longtwo@box
    \fi
    }]%
    \longtwo@repeat
  \endgroup
}

\def\longtwocolumn{\@ifnextchar[\longtwo@\twocolumn}

%\endinput
%%
%% End of file `long2.sty'.
%%
\end{filecontents}

\usepackage{long2}

\parskip0pt plus 8pt

\usepackage{lipsum}

\title{My title}
\author{My the first}

\begin{document}
\longtwocolumn[{%
\maketitle
\begin{tcolorbox}[enhanced jigsaw, 
breakable,
break at=15cm/0pt,                     % <-- !
size=title,
sharp corners,
rounded corners=northeast,
rounded corners=northwest,
colback=Cgreen!25!white,
colframe=Cgreen,
fonttitle=\bfseries,
titlerule=1mm,
titlerule style=black,
title={\center Key Messages},
pad at break=2mm]

\lipsum[1-16]

\end{tcolorbox}

\lipsum[5-10]
}]

\lipsum[16-25]

\end{document}

不过，你也应该考虑使用multicol包，将正文换成双栏环境。这样可能会更简单一些。

\documentclass{article}
\usepackage{geometry,graphicx,xcolor,enumitem,amsmath,caption}

\definecolor{Cgreen}{RGB}{41,106,48}%LIGHT
\usepackage[most]{tcolorbox}

\usepackage{multicol}
\parskip0pt plus 8pt

\usepackage{lipsum}

\title{My title}
\author{My the first}

\begin{document}
\maketitle
\begin{tcolorbox}[enhanced jigsaw, 
breakable, 
size=title,
sharp corners,
rounded corners=northeast,
rounded corners=northwest,
colback=Cgreen!25!white,
colframe=Cgreen,
fonttitle=\bfseries,
titlerule=1mm,
titlerule style=black,
title={\center Key Messages},
pad at break=2mm]

\lipsum[1-6]

\end{tcolorbox}

\lipsum[5-10]

\begin{multicols}{2}%
\lipsum[16-25]
\end{multicols}

\end{document}

Answer 1