例子中，如何显示出R点的坐标值是（2,2）？现在是pt长度单位，不太符合习惯。

 \documentclass{standalone}
  \usepackage{xeCJK} 
  \usepackage{tikz} 
  \usepackage{color} 
  \usetikzlibrary{calc}
   \newdimen\XCoord \newdimen\YCoord \newcommand*{\ExtractCoordinate}[1]{\path (#1); \pgfgetlastxy{\XCoord}{\YCoord};} \newcommand*{\LabelCurrentCoordinate}[2]{\fill [#1] ($(\XCoord,\YCoord)$) circle (2pt) node [above right] {#2}}
\begin{document} 
\begin{tikzpicture}
\draw[->] (-5.2,0)--(5.2,0);
\draw[->] (0,-5.2)--(0,5.2);
\foreach \x in {0,1,...,8}
{    \draw[xshift=\x cm] (-4,0) -- (-4,0.1);
    \draw[yshift=\x cm] (0,-4) -- (0.1,-4);
};  
\node[below] at (0.2,0){0};
\foreach \x in {-4,-3,...,-1}
\node[below] at(\x,0){\x};
\foreach \y in {1,2,...,4}
\node[below] at(\y,0){\y};
\foreach \y in {-4,-3,...,-1}
\node[left] at(0,\y){\y};
\foreach \y in {1,2,...,4}
\node[left] at(0,\y){\y};
%%%
\node[black](g) at(2,2){R};
\ExtractCoordinate{$(g)$}; 
\LabelCurrentCoordinate{blue}  { (\XCoord,\YCoord) };
\end{tikzpicture}
\end{document} 

查看更多