Question

例如，第一个包含选项A和选项B的组合框。如果我在第一个组合框中选择选项A，则第二个组合框包含选项1,2,3,4,5。如果我在第一个组合框中选择选项B，则第二个组合框包含选项a，b，c，d，e。

我怎么能在PyQt5中这样做？我搜索过Qcombobox类，有2个类 activated 和 currentIndexChanged ，但不知道我需要使用哪个以及如何使用它在PyQt5中。

Answer 1

我就是这样做的：

import sys
from PyQt5 import QtWidgets


class ComboWidget(QtWidgets.QWidget):

    def __init__(self, parent=None):
        super(ComboWidget, self).__init__(parent)
        self.setGeometry(50, 50, 200, 200)

        layout = QtWidgets.QVBoxLayout(self)

        self.comboA = QtWidgets.QComboBox()
        # The second addItem parameter is itemData, which we will retrieve later
        self.comboA.addItem('A', ['1', '2', '3', '4'])
        self.comboA.addItem('B', ['a', 'b', 'c', 'd', 'e'])
        self.comboA.currentIndexChanged.connect(self.indexChanged)
        layout.addWidget(self.comboA)

        self.comboB = QtWidgets.QComboBox()
        # We could have added the 1,2,3,4 items directly, but the following
        # is a bit more generic in case the combobox starts with a different
        # index for some reason:
        self.indexChanged(self.comboA.currentIndex())
        layout.addWidget(self.comboB)

        self.show()

    def indexChanged(self, index):
        self.comboB.clear()
        data = self.comboA.itemData(index)
        if data is not None:
            self.comboB.addItems(data)


def main():
    app = QtWidgets.QApplication(sys.argv)
    w = ComboWidget()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

这样，您的代码就会更加面向未来，因为如果您希望在某些时候这样做，它可以很容易地添加/修改/删除任何下拉列表中的项目。

Answer 2

我通过使用3个组合框（让我们称之为x，y和z）来实现它

x包含A，B，用于选择其他组合框中显示的选项。选择A显示组合框y并选择B显示组合框z
y包含1,2,3,4
Z包含a，b，c，d

我使用QStackedLayout代替第二个组合框，用两个组合框（y和z）加载它，并根据在combobox x中选择的选项一次显示其中一个。

方法comboOptionChanged处理此问题。只要选择了组合框x中的不同选项，此方法就会调用。

import sys
from PyQt5.QtWidgets import QWidget, QComboBox, QApplication, QFormLayout, QLabel,QStackedLayout

class DynamicComboExample(QWidget):
    def __init__(self):
        super().__init__()
        self.setupUI()

    def setupUI(self):
        self.setGeometry(300,300, 500, 300)
        self.show()

        combo_a = QComboBox(self)
        combo_a.addItem('A')
        combo_a.addItem('B')

        # set slot for when option of combobox A is changed
        combo_a.currentIndexChanged[int].connect(self.comboOptionChanged)

        self.combo_b = QComboBox()
        self.combo_b.addItem('1')
        self.combo_b.addItem('2')
        self.combo_b.addItem('3')
        self.combo_b.addItem('4')

        self.combo_c = QComboBox()
        self.combo_c.addItem('a')
        self.combo_c.addItem('b')
        self.combo_c.addItem('c')
        self.combo_c.addItem('d')
        self.combo_c.addItem('e')

        # use a stacked layout to view only one of two combo box at a time
        self.combo_container_layout = QStackedLayout()

        self.combo_container_layout.addWidget(self.combo_b)
        self.combo_container_layout.addWidget(self.combo_c)

        combo_container = QWidget()
        combo_container.setLayout(self.combo_container_layout)

        form_layout = QFormLayout()

        form_layout.addRow(QLabel('A:\t'), combo_a)

        # the stacked layout is placed in place of the (meant to be) second combobox
        form_layout.addRow(QLabel('B:\t'), combo_container)


        self.setLayout(form_layout)


    def comboOptionChanged(self, idx):
        ''' gets called when option for combobox A is changed'''

        # check which combobox_a option is selected ad show the appropriate combobox in stacked layout
        self.combo_container_layout.setCurrentIndex(0 if idx == 0 else 1)


def main():
    app= QApplication(sys.argv)
    w = DynamicComboExample()
    exit(app.exec_())

if __name__ == '__main__':
    main()

PyQt中的Qcombobox，如何在一个组合框中设置选项，这取决于其他组合框的选择？

2 个答案: