如何在QComboBox中拦截鼠标信号

我在QDialog小部件上放置了一个自定义组合框，但无法捕获任何鼠标信号。我将QComboBox划分为子类，以拦截QComboBox没有提供的两个信号：LostFocusEvent和mouseDobleClickEvent。LostFocusEvent效果很好，但是该组合没有触发鼠标事件。我在组合框上需要三个信号，并且只提供了一个合适的信号。

我试图设置combo.grabMouse（），而无视文档警告，并且combo.doubleClicked开始工作，但是通过信号连接的所有其他小部件开始行为异常。还尝试了combo.view（）。doubleClick.connect获得类似结果。我也尝试了其他鼠标事件，但结果类似（Press- Release-等）。最后，我尝试在comboBox子类中使用事件而不是QMouseEvent，但是它被focusOutEvent插槽拦截了。鼠标事件在QPushButton上起作用，包括使用Windows 8 Python 3.7 PyQt5双击QTableView小部件。

`class Agreement(QDialog):
    def __init__(self,db, address, parent=None):
        super().__init__(parent= None)
        self.parent = parent
.......................................

    def setUi(self):
    .....................................
        self.comboSupplier = ComboFocus.FocusCombo(self)
        self.comboSupplier.setMaximumSize(220,30)
        self.comboSupplier.setEditable(True)
        #self.comboSupplier.grabMouse()
        self.comboSupplier.activated.connect(self.supplierChange)
        self.comboSupplier.focusLost.connect(self.supplierFocusLost)
        self.comboSupplier.doubleClicked.connect(self.editContact)
    ...........................................

     def supplierChange(self):
        try:
            row = self.comboSupplier.currentIndex()
            idx = self.comboSupplier.model().index(row,0)
            self.supplierId = self.comboSupplier.model().data(idx)
            self.agreementTitle[0] = self.comboSupplier.currentText()
            self.setAgreementTitle()
            self.okToSave[2] = int(self.supplierId)
            self.okSaving()
        except TypeError as err:
            print('supplierChange' + type(err).__name__ + ' ' + err.args[0])

    @pyqtSlot()
    def editContact(self):
        try:
            c = Contacts(self.db,self.comboSupplier.currentText(), 
                APM.OPEN_EDIT_ONE, self.supplierId,parent=self)
            c.show()
            c.exec()
        except Exception as err:
            print(type(err).__name__, err-args)

    @pyqtSlot(ComboFocus.FocusCombo)
    def supplierFocusLost(self, combo):
        try:
            self.setFocusPolicy(Qt.NoFocus)
            name = combo.currentText()
            if combo.findText(name) > -1:
                return
       ........................................

class FocusCombo(QComboBox):
    focusLost = pyqtSignal(QComboBox)
    focusGot = pyqtSignal(QComboBox)
    doubleClicked = pyqtSignal(QComboBox)

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

    def mouseDoubleClickEvent(self,event=QMouseEvent.MouseButtonDblClick):
        print("double click detected")

        self.doubleClicked.emit(self)

    def focusOutEvent(self, event):
        if event.gotFocus():
            self.focusGot.emit(self)

        elif event.lostFocus():
            self.focusLost.emit(self)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    cb = FocusCombo()
    cb.show()
    app.exec_()
    sys.exit(app.exec_())

我想双击comboBox来打开一个小部件来动态编辑联系人属性。