ConTeXt \definedescription：如何在其自己的行上获取描述的标签？

Question

ConTeXt：如何获取多级描述？contextgarden 示例不起作用显示了如何获取嵌套描述，但每个描述都与其描述的标签在同一行开始。如何让描述从新行开始，以便标签单独占一行？

上述答案中描述的 ConTeXt 代码是

\setuppapersize[A5]
\definedescription
  [descr]
  [
    headstyle=bold, 
    style=normal,
    align=flushleft,
    alternative=hanging, 
    width=broad,
    margin=1cm,
  ]

\starttext
\startdescr{Para}
  This is a shorter item label, and some text that talks about it.
  The text is wrapped into a paragraph, with successive lines indented.

  This is another paragraph under the "Para" item.
  \startdescr{Sub Item}  
    This is a description of an item which is within the "Para" item.
  \stopdescr
  \startdescr{Sub Item} 
    Another Sub Item 
  \stopdescr
\stopdescr
\startdescr{Short}
  A short item that's not part of that really long "Para" item.
\stopdescr

\stoptext

并产生格式如下的文本：

Para   This is a shorter item label, and some text that
    talks about it.  The text is wrapped into a paragraph,
    with successive lines indented.
    This is another paragraph under the "Para" item.

    Sub Item   This is a description of an item which
         is within the "Para" item.

    Sub Item   Another Sub Item.

Short    A short item that's not part of that really long
    "Para" item.

我所寻找的内容如下：

Para   
    This is a shorter item label, and some text that talks
    about it.  The text is wrapped into a paragraph, with
    successive lines indented.
    This is another paragraph under the "Para" item.

    Sub Item
        This is a description of an item which is within
        the "Para" item.

    Sub Item
        Another Sub Item.

Short
    A short item that's not part of that really long
    "Para" item.

我尝试了各种各样的方法，使用 \definedescription 的 'command'、'before'、'inbetween'、'after'、'headcommand' 选项（参见http://wiki.contextgarden.net/Command/setupdescriptions), 以及 \crlf, \par, \vspace，但我尝试的任何方法都没有产生预期的效果。

Answer 1

要将描述的标题放在内容之前，您必须alternative=top在设置中使用。由于使用键时标题的缩进量与内容的缩进量相同，因此您必须使用与键一起应用的margin将其移动到左侧。\offsetheadcommand

\define[1]\DescriptionHeadCommand
  {\offset[leftoffset=-1cm]{#1}}

\definedescription
  [descr]
  [alternative=top,
   margin=1cm,
   headcommand=\DescriptionHeadCommand]

\showframe[text][text]

\starttext

\startdescr{Knuth}
\input knuth
\stopdescr

\stoptext