试试下面的代码。
\documentclass{article}
\usepackage{geometry}
\geometry{papersize={16cm,9cm}, hmargin=2cm,vmargin=1.5cm}
\usepackage{tikz}
\begin{document}
XXXXX XXXXX XXXXX XXXXX
XXXXX XXXXX XXXXX XXXXX
XXXXX XXXXX XXXXX XXXXX
\begin{tikzpicture}[remember picture]
\node[draw=red](A)at(1,1){something};%
\path (A.south west);%
\pgfgetlastxy{\Ax}{\Ay}%
\path [overlay] (current page.south west);%
\pgfgetlastxy{\Px}{\Py}%
\pgfmathparse{\Ax-\Px}%
\edef\APx{\pgfmathresult pt}
\pgfmathparse{\Ay-\Py}%
\edef\APy{\pgfmathresult pt}
\edef\APcoord{\APx,\APy}%
\draw [overlay] (current page.south west) -- node[sloped,align=left]{\APx,\\ \APy} ++(\APcoord);%
\end{tikzpicture}
XXXXX XXXXX XXXXX XXXXX
XXXXX XXXXX XXXXX XXXXX
XXXXX XXXXX XXXXX XXXXX
\end{document}
结果如图: