我想要画这样的东西：
除了那个圆圈以外，我什么都知道。这是我的代码：
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes,shapes.geometric,arrows,fit,calc,positioning,automata,}
\usepackage{amsmath}
\begin{document}
\begin{tikzpicture}[shorten >=1pt,auto,node distance=3 cm, scale = 1.0, transform shape]
\tikzstyle{int}=[draw, minimum size=4em]
\tikzset{every edge/.append style={font=\Large}}
\tikzset{every node/.append style={font=\Large}}
\node[state,minimum size=3 cm] (A) {};
\node[state,minimum size=3 cm] (B) [right of=A,node distance=6 cm] {};
\node[int] (C) [above of=A] { };
\node[int] (D) [below of=A] { };
\node[int] (E) [above of=B] { };
\node[int] (F) [below of=B] { };
\path[->] (A) edge [] node [] {} (C);
\path[->] (C) edge [] node [] {} (E);
\path[->] (E) edge [] node [] {} (B);
\path[->] (B) edge [] node [] {} (F);
\path[->] (F) edge [] node [] {} (D);
\path[->] (D) edge [] node [] {} (A);
\end{tikzpicture}
\end{document}
输出为：
答案1
以下是使用\foreach及其语法的evaluate=<variable> as <macro> using <formula>一种可能性count=<macro> from <value>：
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes,shapes.geometric,arrows,fit,calc,positioning,automata,}
\usepackage{amsmath}
\definecolor{myblue}{RGB}{153,205,255}
\begin{document}
\begin{tikzpicture}[shorten >=1pt,auto,node distance=3 cm, scale = 1.0, transform shape,>=latex]
\tikzset{int/.style={draw, minimum size=4em,fill=myblue}}
\tikzset{every edge/.append style={font=\Large}}
\tikzset{every node/.append style={font=\Large}}
\node[state,minimum size=3 cm,fill=myblue] (A) {};
\node[state,minimum size=3 cm,fill=myblue] (B) [right of=A,node distance=6 cm] {};
\node[int] (C) [above of=A] { };
\node[int] (D) [below of=A] { };
\node[int] (E) [above of=B] { };
\node[int] (F) [below of=B] { };
\path[->] (A) edge [] node [] {} (C);
\path[->] (C) edge [] node [] {} (E);
\path[->] (E) edge [] node [] {} (B);
\path[->] (B) edge [] node [] {} (F);
\path[->] (F) edge [] node [] {} (D);
\path[->] (D) edge [] node [] {} (A);
\draw[<-] (A.180) -- +(-0.5,0);
\draw[->] (B.0) -- +(0.5,0);
\foreach \angle [evaluate=\angle as \langle using 180+\angle] in {0,45,90,135}
{
\draw (A.\angle) -- (A.\langle);
\draw (B.\angle) -- (B.\langle);
}
\foreach \angle [evaluate=\angle as \labangle using \angle+67.5,count=\anglei from 0] in {0,-45,...,-315}
\node at ( $ (A) + (\labangle:1cm) $ ) {\anglei};
\end{tikzpicture}
\end{document}
为了获取圆上的标签，可以始终使用\foreach两个显式变量的循环：第一个变量控制标签的角度，另一个变量控制标签本身；当然，如果角度和标签之间存在某种关系，则可以使用语法evaluate=<variable> as <macro> using <formula>来简化事情；以下示例说明了这一点：
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc,positioning,automata}
\definecolor{myblue}{RGB}{153,205,255}
\begin{document}
\begin{tikzpicture}
\node[state,minimum size=3 cm,fill=myblue] (A) {};
\node[state,minimum size=3 cm,fill=myblue] (B) [right of=A,node distance= 6cm] {};
\foreach \angle [evaluate=\angle as \langle using 180+\angle] in {0,45,90,135}
{
\draw (A.\angle) -- (A.\langle);
\draw (B.\angle) -- (B.\langle);
}
\foreach \angle/\label in {67.5/-5,22.5/4,-22.5/6,-67.5/-1,-112.5/7,-157.5/-8,-202.5/-2,-247.5/0}
\node at ( $ (A) + (\angle:1cm) $ ) {\label};
\foreach \angle [evaluate=\angle as \langle using (292.5+\angle)/30] in {67.5,22.5,...,-247.5}
\node at ( $ (B) + (\angle:1cm) $ ) {\langle};
\end{tikzpicture}
\end{document}
答案2
我的评论中提到的形状可以从以下简单的代码中获得：
\documentclass[a4paper]{article}
\usepackage{tikz}
\usetikzlibrary{shapes,positioning}
\begin{document}
\begin{tikzpicture}[node distance=1cm,blue]
\centering
\node[circle split,draw,] (s1) {Circle \nodepart{lower} split};
\node[forbidden sign,text width=4em, text centered,below=of s1,draw] (s2) {Forbidden sign};
\node[cross out,below=of s2,draw] (s3) {Cross out};
\end{tikzpicture}
\end{document}
结果如下：
