Using DataBase and Dict to Add PyQt5 Menus and Tri

问题:

Im trying to make my menu auto generated using this for loop:

q3 = connect_menu.addMenu('Q3')
q3menus = {}
x = 0
for element in q3s:
    key = 'Q'+str(x)
    q3menus[key] = QAction(element[7], self)
    q3.addAction(q3menus[key])
    q3menus[key].triggered.connect(lambda: self.main_form.consavesv(q3menus[key].text()))
    x += 1

q3s equals to a Fetchall function that gets the data from last SQL Query

q3s = [(1, 'Q3', '127.0.0.1', 28960, "Server Test Name", '5154', '127.0.0.1:28960', "127.0.0.1:28960 | Server Test Name"), (2, 'Q3', '192.168.1.66', 28960, 'Server Test 2', '5154', '192.168.1.66:28960', '192.168.1.66:28960 | Server Test 2')]

I tried to use a dictianory, This dictianory adds menu labels as well as it should, but when I click on them I they all have the same triggered.connect() as the last one does..

What Im doing wrong ? I dont want to create Signals myself in here, Cause the Database Results are not static..

Sorry for bad English.

回答1:

he problem is the way you pass the parameters to a lambda function, the correct syntax is:

f = lambda p_1, p_2, ..., p_n: some operation with p_1, p_2, ..., p_n

In your case you must also take into account that the triggered signal of QAction returns a value called checked, so you must precede that parameter as shown below:

q3menus[key].triggered.connect(lambda checked, key=key: self.main_form.consavesv(q3menus[key].text()))

In addition to this approach you can also use the sender() method that returns the object that emits the signal and get the text directly as shown in the following example:

class Example(QMainWindow):
    def __init__(self, parent = None):
        QMainWindow.__init__(self, parent)

        q3s = [(1, 'Q3', '127.0.0.1', 28960, "Server Test Name", '5154', '127.0.0.1:28960', "127.0.0.1:28960 | Server Test Name"), 
        (2, 'Q3', '192.168.1.66', 28960, 'Server Test 2', '5154', '192.168.1.66:28960', '192.168.1.66:28960 | Server Test 2')]
        menubar = self.menuBar()

        q3 = menubar.addMenu("Q")
        q3menus = {}
        for x, element in enumerate(q3s):
            key = 'Q'+str(x)
            q3menus[key] = QAction(element[7], self)
            q3.addAction(q3menus[key])
            q3menus[key].triggered.connect(lambda checked, key=key : self.someFunction(q3menus[key].text()))
            q3menus[key].triggered.connect(self.anotherFuntions)

    def someFunction(self, text):
        print("someFunction {}".format(text))

    def anotherFuntions(self):
        print("anotherFuntions {}".format(self.sender().text()))

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