先甩结论，太晚了，想睡觉。
思路来源于 Stackexchange。我之前也尝试过几个软件，但我还是想上课只带iPad，然后远程Linux使用VNC或者xrdp实在是太不优雅，而且延迟颇高。最终还是准备用Overleaf+LaTeX插入PDF Pages来做批注。
Stackexchange上作者给出的解答是：
\documentclass{article}
%\url{http://tex.stackexchange.com/q/85651/86}
\usepackage[svgnames]{xcolor}
\usepackage{pdfpages}
\usepackage{tikz}
\tikzset{
every node/.style={
anchor=mid west,
}
}
\makeatletter
\pgfkeys{/form field/.code 2 args={\expandafter\global\expandafter\def\csname field@#1\expandafter\endcsname\expandafter{#2}}}
\newcommand{\place}[3][]{\node[#1] at (#2) {\csname field@#3\endcsname};}
\makeatother
\newcommand{\xmark}[1]{\node at (#1) {X};}
\begin{document}
\foreach \mykey/\myvalue in {
ctsfn/{Defined in Week 1},
metsp/{Defined in Week 3},
} {
\pgfkeys{/form field={\mykey}{\myvalue}}
}
\includepdf[
pages=1,
picturecommand={%
\begin{tikzpicture}[remember picture,overlay]
%%% The next lines draw a useful grid - get rid of them (comment them out) on the final version
\draw[gray] (current page.south west) grid (current page.north east);
\foreach \k in {1,...,28} {
\path (current page.south east) ++(-2,\k) node {\k};
}
\foreach \k in {1,...,20} {
\path (current page.south west) ++(\k,2) node {\k};
}
%%% grid code ends here
\tikzset{every node/.append style={fill=Honeydew,font=\large}}
\place[name=ctsfn]{14cm,17cm}{ctsfn}
\place[name=metsp]{11cm,9cm}{metsp}
\draw[ultra thick,blue,->] (ctsfn) to[out=135,in=90] (9cm,17.3cm);
\draw[ultra thick,blue,->] (metsp) to[out=155,in=70] (6cm,9cm);
\end{tikzpicture}
}
]{tikzmark_example.pdf}
\end{document}原作者的效果图：
这个我一看就很心水，因为：
- 有坐标格子，插入annotation很方便；
- 可扩展性强，图文混排，插TiKZ的图，公式，都可以做到。
但是, 有几个问题：
- 老师下发的Beamer文件是横屏的，这个编译出来是竖版；
- 这里宏定义有点乱，而且我不需要飞线啊之类的东西；而且每次include page都太长，不优雅。
- 这里坐标太丑了。
所以我来解决一下：
\usepackage[paperwidth=12cm, paperheight=16cm, landscape]{geometry}使用Geometry让他变为横板。定义一个宏来简化 includepdf 的使用，并支持多个批注
\newcommand{\includePDFWithAnnotations}[2]{ \includepdf[ pages=#1, picturecommand={% \begin{tikzpicture}[remember picture,overlay] %%% The next lines draw a useful grid - get rid of them (comment them out) on the final version \draw[very thin, lightgray] (current page.south west) grid (current page.north east); \foreach \k in {0,...,11} { \path (current page.south east) ++(-0.55,\k + 0.2) node[font=\tiny] {\k}; } \foreach \k in {0,...,14} { \path (current page.south west) ++(\k,0.2) node[font=\tiny] {\k}; } %%% grid code ends here \tikzset{every node/.append style={fill=Honeydew,font=\huge}} % 遍历批注列表并放置批注 #2 \end{tikzpicture} } ]{YOUR PDF NAME.pdf} }优雅地使用宏，插入多个批注：
\includePDFWithAnnotations{1}{ \place{5, 4}{$123avd$} \place{7, 8}{$456xyz$} } \includePDFWithAnnotations{7}{ \place{5, 4}{$123avd$} \place{7, 8}{$456xyz$} }- 把坐标的grid移动到页面边缘，字体变成tiny，线条变细、颜色变淡。美学效果好。
是不是很爽！
最后贴上完整的TeX示例：
\documentclass[UTF8]{ctexart}
\usepackage[svgnames]{xcolor}
\usepackage[paperwidth=12cm, paperheight=16cm, landscape]{geometry}
\usepackage{pdfpages}
\usepackage{tikz}
\tikzset{
every node/.style={
anchor=mid west,
}
}
\makeatletter
\pgfkeys{/form field/.code 2 args={\expandafter\global\expandafter\def\csname field@#1\expandafter\endcsname\expandafter{#2}}}
\newcommand{\place}[2]{\node at (#1) {#2};}
\makeatother
\newcommand{\xmark}[1]{\node at (#1) {X};}
\newcommand{\includePDFWithAnnotations}[2]{
\includepdf[
pages=#1,
picturecommand={%
\begin{tikzpicture}[remember picture,overlay]
%%% The next lines draw a useful grid - get rid of them (comment them out) on the final version
\draw[very thin, lightgray] (current page.south west) grid (current page.north east);
\foreach \k in {0,...,11} {
\path (current page.south east) ++(-0.55,\k + 0.2) node[font=\tiny] {\k}; % 调整字体大小
}
\foreach \k in {0,...,14} {
\path (current page.south west) ++(\k,0.2) node[font=\tiny] {\k}; % 调整字体大小
}
%%% grid code ends here
\tikzset{every node/.append style={fill=Honeydew,font=\huge}}
% 遍历批注列表并放置批注
#2
\end{tikzpicture}
}
]{LA1-4.pdf}
}
\begin{document}
\includePDFWithAnnotations{1}{
\place{5, 4}{$123avd$}
\place{7, 8}{$456xyz$}
}
\includePDFWithAnnotations{7}{
\place{5, 4}{$123avd$}
\place{7, 8}{$456xyz$}
}
\end{document}