创建子菜单

效果如下：
代码如下：
 1 """
 2 ZetCode PyQt5 tutorial
 3 This program creates a submenu.
 4 """
 5 
 6 import sys
 7 from PyQt5.QtWidgets import QMainWindow, QAction, QMenu, QApplication
 8 
 9 
10 class Example(QMainWindow):
11 
12     def __init__(self):
13         super().__init__()
14 
15         self.initUI()
16 
17     def initUI(self):
18 
19         menubar = self.menuBar()
20         fileMenu = menubar.addMenu('File')
21 
22         # New menu is created with QMenu. 
23         impMenu = QMenu('Import', self)
24         impAct = QAction('Import mail', self)
25         # An action is added to the submenu with addAction(). 
26         impMenu.addAction(impAct)
27 
28         newAct = QAction('New', self)
29 
30         fileMenu.addAction(newAct)
31         fileMenu.addMenu(impMenu)
32 
33         self.setGeometry(300, 300, 300, 200)
34         self.setWindowTitle('Submenu')
35         self.show()
36 
37 
38 if __name__ == '__main__':
39 
40     app = QApplication(sys.argv)
41     ex = Example()
42     sys.exit(app.exec_())