python - QListView 中的复选框选择

Question

我开发了一个带有复选框的简单对话框，允许用户从列表中选择一个或多个项目。除了标准的确定和取消按钮外，它还添加了全选和取消全选按钮，允许用户一次选中/取消选中所有项目(这对于大型列表很方便)。

import os, sys
from PyQt4 import Qt, QtCore, QtGui

class ChecklistDialog(QtGui.QDialog):
    def __init__(self, name, stringlist=None, checked=False, icon=None, parent=None):
        super(ChecklistDialog, self).__init__(parent)

        self.name = name
        self.icon = icon
        self.model = QtGui.QStandardItemModel()
        self.listView = QtGui.QListView()

        if stringlist is not None:
            for i in range(len(stringlist)):
                item = QtGui.QStandardItem(stringlist[i])
                item.setCheckable(True)
                check = QtCore.Qt.Checked if checked else QtCore.Qt.Unchecked
                item.setCheckState(check)
                self.model.appendRow(item)

        self.listView.setModel(self.model)

        self.okButton = QtGui.QPushButton("OK")
        self.cancelButton = QtGui.QPushButton("Cancel")
        self.selectButton = QtGui.QPushButton("Select All")
        self.unselectButton = QtGui.QPushButton("Unselect All")

        hbox = QtGui.QHBoxLayout()
        hbox.addStretch(1)
        hbox.addWidget(self.okButton)
        hbox.addWidget(self.cancelButton)
        hbox.addWidget(self.selectButton)
        hbox.addWidget(self.unselectButton)

        vbox = QtGui.QVBoxLayout()
        vbox.addWidget(self.listView)
        vbox.addStretch(1)
        vbox.addLayout(hbox)
        
        self.setLayout(vbox)    
        #self.setLayout(layout)
        self.setWindowTitle(self.name)
        if self.icon is not None: self.setWindowIcon(self.icon)

        self.okButton.clicked.connect(self.accept)
        self.cancelButton.clicked.connect(self.reject)
        self.selectButton.clicked.connect(self.select)
        self.unselectButton.clicked.connect(self.unselect)
        
    def reject(self):
        QtGui.QDialog.reject(self)

    def accept(self):
        self.choices = []
        i = 0
        while self.model.item(i):
            if self.model.item(i).checkState():
                self.choices.append(self.model.item(i).text())
            i += 1
        QtGui.QDialog.accept(self)
        
    def select(self):
        i = 0
        while self.model.item(i):
            item = self.model.item(i)
            if not item.checkState():
                item.setCheckState(True)
            i += 1
        
    def unselect(self):
        i = 0
        while self.model.item(i):
            item = self.model.item(i)
            item.setCheckState(False)
            i += 1  

if __name__ == "__main__":
    fruits = ["Banana", "Apple", "Elderberry", "Clementine", "Fig",
        "Guava", "Mango", "Honeydew Melon", "Date", "Watermelon",
        "Tangerine", "Ugli Fruit", "Juniperberry", "Kiwi", "Lemon",
        "Nectarine", "Plum", "Raspberry", "Strawberry", "Orange"]
    app = QtGui.QApplication(sys.argv)
    form = ChecklistDialog("Fruit", fruits, checked=True)
    if form.exec_():
        print("\n".join([str(s) for s in form.choices]))

上面的代码有效，但我对 QListView 的奇怪行为感到困扰:当对话框显示时“check”参数变为 True，所有复选框都显示为带有“X”标记的选中状态(如预期的那样)。但是，当单击“全选”按钮时，复选框会变成灰色(尽管正确选择了项目)。我希望它们显示有“X”标记，以便向用户呈现一致的外观。

见下图。

一般来说，我的问题是:如何控制复选框在 QListView 中的显示方式？

Answer 1

问题是因为states引起的QCheckBox 有 3 个:

Qt::Unchecked 0 The item is unchecked.

Qt::PartiallyChecked 1 The item is partially checked. Items in hierarchical models may be partially checked if some, but not all, of their children are checked.

Qt::Checked 2 The item is checked.

如您所见，它们是整数值，当您传递 True 的值时，它被转换为 1，这相当于 Qt::PartiallyChecked 那些您得到的是矩形而不是十字.

解决方案是向它传递正确的值:QtCore.Qt.Checked，如下所示:

import sys
from PyQt4 import Qt, QtCore, QtGui


class ChecklistDialog(QtGui.QDialog):

    def __init__(
        self,
        name,
        stringlist=None,
        checked=False,
        icon=None,
        parent=None,
        ):
        super(ChecklistDialog, self).__init__(parent)

        self.name = name
        self.icon = icon
        self.model = QtGui.QStandardItemModel()
        self.listView = QtGui.QListView()

        for string in stringlist:
            item = QtGui.QStandardItem(string)
            item.setCheckable(True)
            check = \
                (QtCore.Qt.Checked if checked else QtCore.Qt.Unchecked)
            item.setCheckState(check)
            self.model.appendRow(item)

        self.listView.setModel(self.model)

        self.okButton = QtGui.QPushButton('OK')
        self.cancelButton = QtGui.QPushButton('Cancel')
        self.selectButton = QtGui.QPushButton('Select All')
        self.unselectButton = QtGui.QPushButton('Unselect All')

        hbox = QtGui.QHBoxLayout()
        hbox.addStretch(1)
        hbox.addWidget(self.okButton)
        hbox.addWidget(self.cancelButton)
        hbox.addWidget(self.selectButton)
        hbox.addWidget(self.unselectButton)

        vbox = QtGui.QVBoxLayout(self)
        vbox.addWidget(self.listView)
        vbox.addStretch(1)
        vbox.addLayout(hbox)

        self.setWindowTitle(self.name)
        if self.icon:
            self.setWindowIcon(self.icon)

        self.okButton.clicked.connect(self.onAccepted)
        self.cancelButton.clicked.connect(self.reject)
        self.selectButton.clicked.connect(self.select)
        self.unselectButton.clicked.connect(self.unselect)

    def onAccepted(self):
        self.choices = [self.model.item(i).text() for i in
                        range(self.model.rowCount())
                        if self.model.item(i).checkState()
                        == QtCore.Qt.Checked]
        self.accept()

    def select(self):
        for i in range(self.model.rowCount()):
            item = self.model.item(i)
            item.setCheckState(QtCore.Qt.Checked)

    def unselect(self):
        for i in range(self.model.rowCount()):
            item = self.model.item(i)
            item.setCheckState(QtCore.Qt.Unchecked)


if __name__ == '__main__':
    fruits = [
        'Banana',
        'Apple',
        'Elderberry',
        'Clementine',
        'Fig',
        'Guava',
        'Mango',
        'Honeydew Melon',
        'Date',
        'Watermelon',
        'Tangerine',
        'Ugli Fruit',
        'Juniperberry',
        'Kiwi',
        'Lemon',
        'Nectarine',
        'Plum',
        'Raspberry',
        'Strawberry',
        'Orange',
        ]
    app = QtGui.QApplication(sys.argv)
    form = ChecklistDialog('Fruit', fruits, checked=True)
    if form.exec_() == QtGui.QDialog.Accepted:
        print '\n'.join([str(s) for s in form.choices])