09-PyQt事件机制.py

import sys

from PyQt5.Qt import *


class APP(QApplication):
    """重写了QApplication类，捕捉并显示事件"""

    def notify(self, receiver, evt):
        if receiver.inherits("QPushButton") and evt.type() == QEvent.MouseButtonPress:
            print(receiver, evt)
        return super().notify(receiver, evt)  # 负责分发


class Btn(QPushButton):
    def event(self, evt):
        if evt.type() == QEvent.MouseButtonPress:
            print(evt)
        return super().event(evt)

    def mousePressEvent(self, *args, **kwargs) -> None:
        print("鼠标被按下了……")
        return super().mousePressEvent(*args, **kwargs)


app = APP(sys.argv)

window = QWidget()
window.resize(500, 500)

btn = Btn(window)
btn.setText("按钮")
btn.move(200, 200)

btn.pressed.connect(lambda: print("cao-按钮被点击了"))

window.show()

sys.exit(app.exec_())