Python 如何使QComboBox下拉菜单保持打开状态

我想知道如何使

QComboBox

下拉菜单保持打开状态

from PyQt4 import QtCore, QtGui    
app = QtGui.QApplication([])

class Combo(QtGui.QComboBox):
    def __init__(self, *args, **kwargs):
        super(Combo, self).__init__()
        self.addItems(['Item_1','Item_2','Item_3','Item_4','Item_5'])
        self.show()

tree=Combo()
sys.exit(app.exec_())

---

为了使

QComboBox

的下拉菜单保持打开状态，可以覆盖其内置的

hidePopup（）

方法

from PyQt4 import QtCore, QtGui    
app = QtGui.QApplication([])

class Combo(QtGui.QComboBox):
    def __init__(self, *args, **kwargs):
        super(Combo, self).__init__()
        self.addItems(['Item_1','Item_2','Item_3','Item_4','Item_5'])
        self.show()

    def hidePopup (self):
        pass

inst=Combo()
sys.exit(app.exec_())