当我使用 tikz 文本时遇到此错误，您能告诉我哪里出了问题吗？
Package pgfkeys Error: The key '/tikz/text' requires a value. I
am going to ignore this key.
See the pgfkeys package documentation for explanation.
Type H <return> for immediate help.
。
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric, arrows}
\tikzstyle{startstop} = [rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30]
\tikzstyle{io} = [trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=2cm, minimum height=1cm, text centered, draw=black, fill=blue!30]
\tikzstyle{process} = [rectangle, minimum width=3cm, minimum height=1cm, text centered, text width=3cm, draw=black, fill=orange!30]
\tikzstyle{decision} = [diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30]
\tikzstyle{arrow} = [thick,->,>=stealth]
\tikzstyle{text} = [text width=0.5cm,text centered]
\title{Communication protocol}
\author{beltagymohamed }
\date{June 2015}
\begin{document}
\maketitle
\section{Introduction}
\newpage
%sadas
\begin{tikzpicture}[node distance=2cm]
\node (in1) [io, below of=start] {Enter Command };
\node (okok) [decision, below of=done, yshift= -2.5cm] {Every thing is O.K.?};
% Connect okok yes to enter command
\draw [arrow] (okok)-| ([xshift=1.5cm] okok.east) |- (in1) ;
\node[text, below left of=okok,xshift= 3.6cm,yshift= 1.6cm] (okokyes) {Yes};
\end{tikzpicture}
\end{document}
答案1
节点start和done未定义，因此我无法使用它们。text正如@Daniel Schlegel 指出的那样，错误在于您无法重新定义它。如果您将其更改为，则Mytext一切正常。
我对您的图表做了一些小改动，请检查是否一切符合您的要求。
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric, arrows, positioning}
\tikzstyle{startstop} = [rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30]
\tikzstyle{io} = [trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=2cm, minimum height=1cm, text centered, draw=black, fill=blue!30]
\tikzstyle{process} = [rectangle, minimum width=3cm, minimum height=1cm, text centered, text width=3cm, draw=black, fill=orange!30]
\tikzstyle{decision} = [diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30]
\tikzstyle{arrow} = [thick,->,>=stealth]
\tikzstyle{Mytext} = [text width=0.5cm,text centered]
\title{Communication protocol}
\author{beltagymohamed }
\date{June 2015}
\begin{document}
\maketitle
\section{Introduction}
\newpage
\begin{tikzpicture}[node distance=2cm]
%Nodes
\node (start) [startstop] {START};
\node (in1) [io, below =of start] {Enter Command };
\node (okok) [decision, below =of in1, yshift= -2.5cm] {Every thing is O.K.?};
\node (stop) [startstop,below = of okok] {STOP};
% Arrows
\draw[arrow] (start.south) to (in1.north);
\draw[arrow] (in1.south) to (okok.north);
\draw [arrow] (okok) -| node[Mytext,pos=0.1,above] (okokyes) {Yes} ([xshift=1.5cm] okok.east) |- (in1) ;
\draw [arrow] (okok.south) -- node[Mytext,pos=0.1,right] (okokno) {No} (stop);
\end{tikzpicture}
\end{document}
得出的结果为：
