更新时在pyQT5中重绘主窗口

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget
from PyQt5.QtGui import QPainter, QColor, QBrush
from PyQt5.QtCore import Qt

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setGeometry(100, 100, 500, 500)
        self.setWindowTitle("重绘主窗口示例")

        self.centralWidget = QWidget(self)
        self.setCentralWidget(self.centralWidget)

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)

        # 绘制背景
        painter.setBrush(QColor(255, 255, 255))
        painter.drawRect(self.rect())

        # 绘制其他内容
        # ...

if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MyWindow()
    window.show()
    sys.exit(app.exec_())