重新造訪節點內的 tikz 文字位置

Question

我正在關注我得到的答案這裡對於之前關於如何控制tikz.我想要一個傾斜的盒子包圍 4 個較小的盒子，然後自動將傾斜盒子的標籤放置在右上角。還不夠遠吧。我可以手動將其強制翻轉，但我會多次執行此操作，並且傾斜的框每次都會改變大小。所以必須反覆進行。

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,fit,backgrounds}

\tikzset{box/.style={draw, minimum width = 1.cm, minimum height = 1.cm, text width=1cm, text centered},
slantedbox/.style={draw,trapezium,trapezium left angle=70,trapezium right angle=-70, label={[shift={(9ex,-3ex)}]north east:#1}}
}

\begin{document}
\begin{tikzpicture}
\node [box] (phiQQ) at (0,0) {$\phi_{QQ}$};
\node [box] (phiQA) at (3,0) {$\phi_{QA}$};
\node [box] (phiQ*A) at (6,0) {$\phi_{Q^*A}$};
\node [box] (phiAA) at (4.5,-2) {$\phi_{AA}$};
\node [slantedbox = $\xi$, fit = (phiQQ)(phiQA)(phiQ*A)(phiAA), minimum height = 2cm] at (3,-1) (xi) {};
\end{tikzpicture}

\end{document}

這是我目前的輸出：

我想要$\xi$自動更右邊。

Answer 1

top right corner用於

slantedbox/.style={draw,trapezium,trapezium left angle=70,
          trapezium right angle=-70, label={[shift={(0,-3ex)}]top right corner:#1}}

可能的錨點是（來自pgfmanual第 705 頁）

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,fit,backgrounds}

\tikzset{box/.style={draw, minimum width = 1.cm, minimum height = 1.cm, text width=1cm, text centered},
slantedbox/.style={draw,trapezium,trapezium left angle=70,
          trapezium right angle=-70, label={[shift={(0,-3ex)}]top right corner:#1}}
}

\begin{document}
\begin{tikzpicture}
\node [box] (phiQQ) at (0,0) {$\phi_{QQ}$};
\node [box] (phiQA) at (3,0) {$\phi_{QA}$};
\node [box] (phiQ*A) at (6,0) {$\phi_{Q^*A}$};
\node [box] (phiAA) at (4.5,-2) {$\phi_{AA}$};
\node [slantedbox = $\xi$, fit = (phiQQ)(phiQA)(phiQ*A)(phiAA), minimum height = 2cm] at (3,-1) (xi) {};
\end{tikzpicture}

\end{document}