PyQt 绘制垂直标签

Question

我想旋转一个 QLabel 使其垂直定向。这里提出了一个类似的问题：PyQT: Rotate a QLabel so that it's positioned diagonally instead of horizontally 但答案中的代码会导致递归循环问题。

这是我正在使用的代码，为什么代码在递归循环中运行，为什么没有绘制标签？：

from PyQt4.QtGui import QLabel, QPainter
from PyQt4.QtCore import QSize
from PyQt4 import QtCore, QtGui
import sys

class VerticalLabel(QLabel):
    def __init__(self, text = ""):
        QtGui.QLabel.__init__(self, text)
        self.text = text

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setPen(QtCore.Qt.black)
        painter.translate(0, self.height()-1)
        painter.rotate(-90)
        self.setGeometry(self.x(), self.y(), self.height(), self.width())
        painter.drawText(0, 0, self.text)
        print("text: {0}".format(self.text))
        painter.end()

    def minimumSizeHint(self):
        size = QLabel.minimumSizeHint(self)
        return QSize(size.height(), size.width())

    def sizeHint(self):
        size = QLabel.sizeHint(self)
        return QSize(size.height(), size.width())

    def setText(self, newText):
        self.text = newText

class Example(QtGui.QWidget):
    def __init__(self):
        super(Example, self).__init__()
        self.initUI()

    def initUI(self):
        lbl1 = VerticalLabel('label 1')
        lbl2 = VerticalLabel('label 2')
        lbl3 = VerticalLabel('label 3')
        hBoxLayout = QtGui.QHBoxLayout()
        hBoxLayout.addWidget(lbl1)
        hBoxLayout.addWidget(lbl2)
        hBoxLayout.addWidget(lbl3) 
        self.setLayout(hBoxLayout)
        self.setGeometry(300, 300, 250, 150) 
        self.show()

def main():
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 1

这是来自另一个答案的相同代码的略微修改版本，请记住，如果您在paintEvent下放置任何打印，如果您在小部件上有任何活动（例如鼠标移动或调整大小或什至触摸），它将每次打印窗口将重绘，因为这是paintEvent 的意思。

class MyLabel(QtGui.QWidget):
    def __init__(self, text=None):
        super(self.__class__, self).__init__()
        self.text = text

    def paintEvent(self, event):
        painter = QtGui.QPainter(self)
        painter.setPen(QtCore.Qt.black)
        painter.translate(20, 100)
        painter.rotate(-90)
        if self.text:
            painter.drawText(0, 0, self.text)
        painter.end()

class Example(QtGui.QWidget):
    def __init__(self):
        super(Example, self).__init__()
        self.initUI()

    def initUI(self):
        lbl1 = MyLabel('lbl 1')
        lbl2 = MyLabel('lbl 2')
        lbl3 = MyLabel('lbl 3')
        hBoxLayout = QtGui.QHBoxLayout()
        hBoxLayout.addWidget(lbl1)
        hBoxLayout.addWidget(lbl2)
        hBoxLayout.addWidget(lbl3) 
        self.setLayout(hBoxLayout)
        self.setGeometry(300, 300, 250, 150) 
        self.show()

def main():
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()