PyQt: 通过自定义类重写QApplication的notify方法捕获捕获应用receiver为QPushButton，event为QEvent.MouseButtonPress的事件

import sys
from PyQt5.Qt import *


# 自定义类，继承类QApplication
class CustomApplication(QApplication):
    # 重写QApplication的notify方法
    def notify(self, a0, a1) -> bool:
        # 捕获receiver为QPushButton，事件为QEvent.MouseButtonPress的事件
        if a0.inherits("QPushButton") and a1.type() == QEvent.MouseButtonPress:
            print(a0, a1, "notify-按钮按下了！")
        return QApplication.notify(self, a0, a1)


class CustomButton(QPushButton):
    def event(self, e) -> bool:
        if e.type() == QEvent.MouseButtonPress:
            print(e, "event-按钮按下了！")
        return QPushButton.event(self, e)

    def mousePressEvent(self, e) -> None:
        print(e, "mousePressEvent-按钮按下了！")
        # mousePressEvent无返回值，所以调用父方法即可，无需返回值
        QPushButton.mousePressEvent(self, e)


class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.label_1 = QLabel()
        self.button_1 = QPushButton()
        self.set_ui()

    def set_ui(self):
        self.resize(300, 300)
        self.setStyleSheet("color:blue")
        self.setWindowTitle("主窗口")
        self.label()
        self.button()
        self.action()
        self.show()

    def label(self):
        self.label_1 = QLabel(self)
        self.label_1.setText("Hello")
        self.label_1.move(100, 100)

    def button(self):
        self.button_1 = CustomButton(self)
        self.button_1.setText("按下试试")
        self.button_1.move(100, 200)

    def action(self):
        self.button_1.clicked.connect(self.push_button)

    def push_button(self):
        self.label_1.setText("World!")
        self.label_1.adjustSize()


if __name__ == '__main__':
    app = CustomApplication(sys.argv)
    window = Window()
    sys.exit(app.exec_())