PyQt5 QCombobox：如何使用用户的选定值来执行特定功能？

Question

"""我已经定义了某些函数来执行密码加密。虽然加密功能正常，但我无法使用使用 PyQt5 编写的 GUI。更具体地说，我无法执行我的函数基于用户在下拉框/QCombobox中选择的加密类型。 """

class App(QMainWindow):

    def __init__(self):
        super().__init__()
        self.title = 'Password encryption'
        self.left = 10
        self.top = 10
        self.width = 400
        self.height = 200
        self.initUI()

    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)

        # Create textbox
        self.textbox = QLineEdit(self)
        self.textbox.move(30, 35)
        self.textbox.resize(350, 30)

        # Create a button in the window
        drop = QComboBox(self)
        drop.addItem("None")
        drop.addItem("modlensq")
        drop.addItem("fishcrypt")
        drop.addItem("bitman")
        drop.addItem("caesarcipher")
        drop.addItem("encryptcipher2")
        drop.addItem("blowfishencryption")
        drop.addItem("AES")
        drop.move(45, 90)

        inp = QLabel(self)
        inp.setText("Enter the password:")
        inp.move(5, 5)

        # Create a drop down list to select in the window
        self.button = QPushButton('Encrypt', self)
        self.button.move(135, 150)

        # connect button to function on_click
        self.button.clicked.connect(self.on_click)
        self.show()


    @pyqtSlot()

    def on_click(self):
        textboxValue = self.textbox.text()

        QMessageBox.question(self, 'password after encryption', "encrypted form: " + textboxValue , QMessageBox.Ok,
                             QMessageBox.Ok)
        self.textbox.setText("")


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = App()
    sys.exit(app.exec_())

Answer 1

添加信号：

 drop.activated[str].connect(self.onActivated)

http://doc.qt.io/qt-5/qcombobox.html#activated-1 当用户在组合框中选择一个项目时发送此信号。

试试看：

from PyQt5 import Qt

class App(Qt.QMainWindow):
    def __init__(self):
        super().__init__()
        self.title = 'Password encryption'
        self.left = 500
        self.top = 100
        self.width = 400
        self.height = 200
        self.comboText = None                                       # +++
        self.initUI()

    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)

        # Create textbox
        self.textbox = Qt.QLineEdit(self)
        self.textbox.move(30, 35)
        self.textbox.resize(350, 30)

        # Create a button in the window
        drop = Qt.QComboBox(self)
        drop.addItem("None")
        drop.addItem("modlensq")
        drop.addItem("fishcrypt")
        drop.addItem("bitman")
        drop.addItem("caesarcipher")
        drop.addItem("encryptcipher2")
        drop.addItem("blowfishencryption")
        drop.addItem("AES")
        drop.move(45, 90)
        drop.activated[str].connect(self.onActivated)                  # +++

        inp = Qt.QLabel(self)
        inp.setText("Enter the password:")
        inp.move(5, 5)

        # Create a drop down list to select in the window
        self.button = Qt.QPushButton('Encrypt', self)
        self.button.move(135, 150)

        # connect button to function on_click
        self.button.clicked.connect(self.on_click)
        self.show()


    @Qt.pyqtSlot()
    def on_click(self):
        textboxValue = self.textbox.text()

        Qt.QMessageBox.question(self, 'password after encryption', 
                                "encrypted form: {}, <br>ComboBoxItem: {} "\
                                .format(textboxValue, self.comboText) ,        # +++
                                Qt.QMessageBox.Ok, Qt.QMessageBox.Ok)
        self.textbox.setText("")

    # +++     
    def onActivated(self, text):
        self.comboText = text        

if __name__ == '__main__':
    import sys
    app = Qt.QApplication(sys.argv)
    ex = App()
    sys.exit(app.exec_())