self.labelSignUp.installEventFilter(self)

def eventFilter(self, obj, event):
        """重写事件过滤器"""
        # 判断事件源是否为目标label，且事件为鼠标点击
        if obj == self.labelSignUp and event.type() == QEvent.MouseButtonPress:
            # 判断是否为左键点击
            if event.button() == Qt.LeftButton:
                print("事件过滤器：Label被左键点击了")
                return True  # 事件已处理
        return super().eventFilter(obj, event)  # 其他事件交给父类处理

class ClickableLabel(QLabel):
    def __init__(self, parent=None):
        super().__init__(parent)

    def mousePressEvent(self, event):
        self.clicked.emit()

    clicked = QtCore.pyqtSignal()

label = ClickableLabel("点击我")
label.clicked.connect(lambda: print("QLabel被点击了"))