python - PyQt:如何将组合框项目设置为可检查？

Question

为了将 GUI 小部件数量保持在最低限度，我需要找到一种方法让用户可以选择下拉菜单项，这些菜单项可用于过滤掉 listWidget 项中显示的内容。假设 listWidget 列出了 5 个不同类别的项目:“Cat A”、“Cat B”、“Cat C”、“Cat D”、“Cat E”。我可以为每个项目类别实现单选或复选框。但是 5 个单选按钮或复选框会占用大量 GUI 空间。带有可检查项目的组合框似乎是一个正确的选择。有什么想法吗？

from PyQt4 import QtGui, QtCore
import sys, os


class CheckableComboBox(QtGui.QComboBox):
    def __init__(self):    
        super(CheckableComboBox, self).__init__()

    def flags(self, index):
        return Qt.ItemIsUserCheckable | Qt.ItemIsSelectable | Qt.ItemIsEnabled


class Dialog_01(QtGui.QMainWindow):
    def __init__(self):
        super(QtGui.QMainWindow,self).__init__()

        myQWidget = QtGui.QWidget()
        myBoxLayout = QtGui.QVBoxLayout()
        myQWidget.setLayout(myBoxLayout)
        self.setCentralWidget(myQWidget)

        self.ComboBox = CheckableComboBox()
        for i in range(3):
            self.ComboBox.addItem("Combobox Item " + str(i))

        myBoxLayout.addWidget(self.ComboBox)


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

Answer 1

这个多选组合的想法有come up before ，但我不确定它是否是最佳解决方案。实际上，所需要的只是一个带有下拉菜单的工具按钮(类似于网络浏览器中的历史记录按钮)。

这是一个基本演示，说明了这两个选项(左侧按钮，右侧组合):

PyQt5:

from PyQt5 import QtWidgets, QtGui, QtCore

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

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

class Dialog_01(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        myQWidget = QtWidgets.QWidget()
        myBoxLayout = QtWidgets.QHBoxLayout()
        myQWidget.setLayout(myBoxLayout)
        self.setCentralWidget(myQWidget)
        self.ComboBox = CheckableComboBox()
        self.toolbutton = QtWidgets.QToolButton(self)
        self.toolbutton.setText('Categories ')
        self.toolmenu = QtWidgets.QMenu(self)
        for i in range(3):
            self.ComboBox.addItem('Category %s' % i)
            item = self.ComboBox.model().item(i, 0)
            item.setCheckState(QtCore.Qt.Unchecked)
            action = self.toolmenu.addAction('Category %s' % i)
            action.setCheckable(True)
        self.toolbutton.setMenu(self.toolmenu)
        self.toolbutton.setPopupMode(QtWidgets.QToolButton.InstantPopup)
        myBoxLayout.addWidget(self.toolbutton)
        myBoxLayout.addWidget(self.ComboBox)

if __name__ == '__main__':

    app = QtWidgets.QApplication(['Test'])
    dialog_1 = Dialog_01()
    dialog_1.show()
    app.exec_()
    
**PyQt4**:

from PyQt4 import QtGui, QtCore

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

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

class Dialog_01(QtGui.QMainWindow):
    def __init__(self):
        super(QtGui.QMainWindow, self).__init__()
        myQWidget = QtGui.QWidget()
        myBoxLayout = QtGui.QHBoxLayout()
        myQWidget.setLayout(myBoxLayout)
        self.setCentralWidget(myQWidget)
        self.ComboBox = CheckableComboBox()
        self.toolbutton = QtGui.QToolButton(self)
        self.toolbutton.setText('Categories ')
        self.toolmenu = QtGui.QMenu(self)
        self.toolbutton.setMenu(self.toolmenu)
        self.toolbutton.setPopupMode(QtGui.QToolButton.InstantPopup)
        for i in range(3):
            self.ComboBox.addItem('Category %s' % i)
            item = self.ComboBox.model().item(i, 0)
            item.setCheckState(QtCore.Qt.Unchecked)
            action = self.toolmenu.addAction('Category %s' % i)
            action.setCheckable(True)
        myBoxLayout.addWidget(self.toolbutton)
        myBoxLayout.addWidget(self.ComboBox)

if __name__ == '__main__':

    app = QtGui.QApplication(['Test'])
    dialog_1 = Dialog_01()
    dialog_1.show()
    app.exec_()