PyQt5 可检查组合框：显示已检查项目列表

Question

基于https://stackoverflow.com/a/22775990/7894940checkable combo box实现，我想更进一步，能够在主QComboBox标签上直接显示选中项的列表，即当显示文本时QComboBox 没有“展开”。

到目前为止，我可以打印检查项目的列表，但我不知道如何用前者更改主 QComboBox 标签文本：

from PyQt5.QtWidgets import QApplication, QComboBox, QMainWindow, QWidget, QVBoxLayout
from PyQt5.QtGui import QStandardItemModel
from PyQt5.QtCore import Qt
import sys


class CheckableComboBox(QComboBox):
    def __init__(self):
        super(CheckableComboBox, self).__init__()
        self.view().pressed.connect(self.handle_item_pressed)
        self.setModel(QStandardItemModel(self))

    def handle_item_pressed(self, index):
        item = self.model().itemFromIndex(index)
        if item.checkState() == Qt.Checked:
            item.setCheckState(Qt.Unchecked)
            # print(item.text() + " was unselected.")
        else:
            item.setCheckState(Qt.Checked)
            # print(item.text() + " was selected.")
        self.check_items()

    def item_checked(self, index):
        item = self.model().item(index, 0)
        return item.checkState() == Qt.Checked

    def check_items(self):
        checkedItems = []
        for i in range(self.count()):
            if self.item_checked(i):
                checkedItems.append(self.model().item(i, 0).text())
        print(checkedItems)


class Dialog_01(QMainWindow):
    def __init__(self):
        super(QMainWindow, self).__init__()
        myQWidget = QWidget()
        myBoxLayout = QVBoxLayout()
        myQWidget.setLayout(myBoxLayout)
        self.setCentralWidget(myQWidget)
        self.ComboBox = CheckableComboBox()
        for i in range(3):
            self.ComboBox.addItem("Combobox Item " + str(i))
            item = self.ComboBox.model().item(i, 0)
            item.setCheckState(Qt.Unchecked)
        myBoxLayout.addWidget(self.ComboBox)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    dialog_1 = Dialog_01()
    dialog_1.show()
    dialog_1.resize(480, 320)
    sys.exit(app.exec_())

一张解释我想要什么的图片：

Answer 1

你可以重写paintEvent方法：

class CheckableComboBox(QComboBox):
    def __init__(self):
        super(CheckableComboBox, self).__init__()
        self.view().pressed.connect(self.handle_item_pressed)
        self.setModel(QStandardItemModel(self))

    def handle_item_pressed(self, index):
        item = self.model().itemFromIndex(index)
        if item.checkState() == Qt.Checked:
            item.setCheckState(Qt.Unchecked)
        else:
            item.setCheckState(Qt.Checked)

    def item_checked(self, index):
        item = self.model().item(index, 0)
        return item.checkState() == Qt.Checked

    def check_items(self):
        checkedItems = []
        for i in range(self.count()):
            if self.item_checked(i):
                checkedItems.append(self.model().item(i, 0).text())
        return checkedItems

    def paintEvent(self, event):
        painter = QStylePainter(self)
        painter.setPen(self.palette().color(QPalette.Text))
        opt = QStyleOptionComboBox()
        self.initStyleOption(opt)
        opt.currentText = ",".join(self.check_items())
        painter.drawComplexControl(QStyle.CC_ComboBox, opt)
        painter.drawControl(QStyle.CE_ComboBoxLabel, opt)

Answer 2

只需对原始代码稍作改动，即可轻松实现以下代码。当您打开组合框选项卡时，您将看到所有项目标签都更新为当前选定的选项。

例子：

1. 如果选择了所有选项，您将获得以下信息：

“组合框项目 0 - 选定项目：0, 1, 2”

或

1. 如果例如选项 0 被删除：

组合框项目 2 - 选定项目：1、2

代码：

    def check_items(self):
        checkedItems = []
        for i in range(self.count()):
            if self.item_checked(i):
                checkedItems.append(i)

        self.update_labels(checkedItems)

    def update_labels(self, item_list):

        n = ''
        count = 0
        for i in item_list:
            if count == 0:
                n += ' %s' % i
            else:
                n += ', %s' % i

            count += 1

#        print('n : "%s".' % n)

        for i in range(self.count()):

            text_label = self.model().item(i, 0).text()

#            print('Current (index %s) text_label "%s"' % (i, text_label))
#            sys.stdout.flush()

            if text_label.find('-') >= 0:
                text_label = text_label.split('-')[0]

            item_new_text_label = text_label + ' - selected item(s): ' + n

#            self.model().item(i).setText(item_new_text_label)
             self.setItemText(i, item_new_text_label)  # copy/paste error corrected.

#        print(item_list)
        sys.stdout.flush()