在我的文档中，我有几个制表环境的实例，它们都看起来像这样：
\startplacetable[location=force,number=no]
\starttabulate[|l|r|rw(2cm)|]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
% --- varying content here, example line: ---
\NC A \NC 200ms \NC 20ms \NC \NR
% -------------------------------------------
\HL
\stoptabulate
\stopplacetable
因此我尝试创建一个自定义的启停环境：
\definestartstop[ProcessTable][
before={%
\startplacetable[location=force,number=no]
\starttabulate[|l|r|rw(2cm)|]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
},%
after={%
\HL
\stoptabulate
\stopplacetable
}%
]
这在文档中使用时永远不会结束，例如：
\starttext
\startProcessTable
\NC A \NC 200ms \NC 20ms \NC \NR
\stopProcessTable
\stoptext
ConTeXt 输出的最后两行：
close source > level 2, order 3, name '/.../test.tex'
close source > level 1, order 3, name '/usr/local/context/tex/texmf-context/tex/context/base/mkiv/cont-yes.mkiv'
当尝试将其与原始代码一起使用时：
\starttext
\startProcessTable
\NC A \NC 200ms \NC 20ms \NC \NR
\stopProcessTable
\startplacetable[location=force,number=no]
\starttabulate[|l|r|rw(2cm)|]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
\stoptabulate
\stopplacetable
\stoptext
我得到这个输出，暗示某些事情严重错误：
tex error > tex error on line 34 in file /.../test.tex: ! Missing } inserted
<inserted text>
}
<to be read again>
\endtemplate
<template> \endtemplate
\tabl_tabulate_column_normal ...\unskip \aligntab
\ifconditional \c_tabl_tab...
\tabl_tabulate_insert_body ...\dotagconstruct \NC
A \NC 200ms \NC 20ms \NC \...
\tabl_tabulate_insert_content ...late_insert_body
\tabl_tabulate_insert_foot...
...
l.34 \stoptabulate
24 %]
25
26 \starttext
27 \startProcessTable
28 \NC A \NC 200ms \NC 20ms \NC \NR
29 \stopProcessTable
30
31 \startplacetable[location=force,number=no]
32 \starttabulate[|l|r|rw(2cm)|]
33 \HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
34 >> \stoptabulate
35 \stopplacetable
36 \stoptext
在尝试解决这个问题时，我发现有\definetabulate，所以我尝试使用它：
\definetabulate[ProcessTable][|l|r|rw(2cm)|]
\setuptabulate[ProcessTable][
before={%
\startplacetable[location=force,number=no]
},
inner={%
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
},
after={%
\stopplacetable
}%
]
这可以编译，但不会呈现表格（即，呈现了标题和正文中的文本，但没有线条和对齐方式）。我假设我使用了inner错误的参数，但我没有找到相关文档或示例。当我删除该参数时inner，表格会呈现，但没有标题。
我该如何正确设置这样的环境？
答案1
看起来\starttabulate是在寻找\stoptabulate，所以把它放进去\definestartstop是行不通的。你可以解决这个问题，只需收集表内容作为参数即可。
\unexpanded\long\def\startProcessTable#1\stopProcessTable
{\startplacetable[location=force,number=no]
\starttabulate[|l|r|rw(2cm)|]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
#1%
\HL
\stoptabulate
\stopplacetable}
\starttext
\startProcessTable
\NC A \NC 200ms \NC 20ms \NC \NR
\stopProcessTable
\stoptext
如果您稍后需要重用表内容，或者以任何方式处理它，我建议使用缓冲区：
\unprotect
\unexpanded\def\startProcessTable
{\buff_pickup{ProcessTable}{startProcessTable}{stopProcessTable}{\relax}{\process_table}{\zerocount}}
\unexpanded\def\process_table
{\startplacetable[location=force,number=no]
\starttabulate[|l|r|rw(2cm)|]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
\rawbuffer{ProcessTable}%
\HL
\stoptabulate
\stopplacetable}
\protect
\starttext
\startProcessTable
\NC A \NC 200ms \NC 20ms \NC \NR
\stopProcessTable
\stoptext
答案2
为了使表格具有特定的第一行和最后一行，您可以使用\starttablehead和\starttabletail（中有一个错误tabl-tbl.mkiv；我会将错误修复发送到上下文列表，但同时，我也在下面包含了修复）。
\starttabulatehead
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
\stoptabulatehead
\starttabulatetail
\HL
\stoptabulatetail
\starttext
\starttabulate[|l|r|rw(2cm)|]
\NC A \NC 200ms \NC 20ms \NC \NR
\NC B \NC 400ms \NC 30ms \NC \NR
\stoptabulate
\stoptext
但是，这会给每个表添加一个头和尾。要将它们应用于特定表，我们可以简单地定义一个新的制表符：
\definetabulate[process][|l|r|rw(2cm)|]
\starttabulatehead[process]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
\stoptabulatehead
\starttabulatetail[process]
\HL
\stoptabulatetail
\starttext
\startprocess
\NC A \NC 200ms \NC 20ms \NC \NR
\NC B \NC 400ms \NC 30ms \NC \NR
\stopprocess
\stoptext
现在，如果您使用浮点数使表格居中，则可以添加：
\setuptabulate
[process]
[
before={\startplacetable[location={force,none}]\insidefloatfalse},
after={\stopplacetable},
]
需要\insidefloatfalse确保after应用了键；否则，ConTeXt 以外部模式启动，应用之前键，并且当应用之后键时，它会检查表是否位于浮点数内并且不应用之后键！
以下是完整的代码（修复了错误tabl-tab.mkiv）
\unprotect
\def\tabl_tabulate_check_full_content % - needed, else confusion with \c!header
{\ifcsname\??tabulatehead\currenttabulation\endcsname
%\expandafter\ifx\csname\??tabulatehead\currenttabulation\endcsname\empty
\expandafter\ifx\lastnamedcs\empty
\let\tabl_tabulate_insert_head\empty
\else
\let\tabl_tabulate_insert_head\tabl_tabulate_insert_head_content
\fi
\else
\let\tabl_tabulate_insert_head\empty
\fi
\ifcsname\??tabulatefoot\currenttabulation\endcsname
\expandafter\ifx\csname\??tabulatefoot\currenttabulation\endcsname\empty
%\expandafter\ifx\lastnamedcs\empty
\let\tabl_tabulate_insert_foot\empty
\else
\let\tabl_tabulate_insert_foot\tabl_tabulate_insert_foot_content
\fi
\else
\let\tabl_tabulate_insert_foot\empty
\fi}
\protect
\definetabulate[process][|l|r|rw(2cm)|]
\setuptabulate
[process]
[
before={\startplacetable[location={force,none}]\insidefloatfalse},
after={\stopplacetable},
]
\starttabulatehead[process]
\HL \NC {\bf Process} \NC {\bf\em T} \NC {\bf\em C} \NC \NR \HL
\stoptabulatehead
\starttabulatetail[process]
\HL
\stoptabulatetail
\starttext
\input knuth
\startprocess
\NC A \NC 200ms \NC 20ms \NC \NR
\NC B \NC 400ms \NC 30ms \NC \NR
\stopprocess
\input knuth
\startprocess
\NC A \NC 200ms \NC 20ms \NC \NR
\NC B \NC 400ms \NC 30ms \NC \NR
\stopprocess
\input knuth
\stoptext
这使
