PySide中的QComboBox自动补全无法工作，但在PyQt4中可以

Question

我有一个组合框，里面用了一种自定义的自动补全功能，在PyQt4中运行得很好，但在PySide中却不行。

我确认新的自动补全功能已经替换了QComboBox自带的那个，因为现在没有内联补全了。但是在PySide中运行时，自动补全的下拉列表没有出现，选项也没有过滤出来。

我还尝试确保所有的文本都是str类型或者都是unicode类型，以避免PyQt API 1中使用QString和PySide中使用Python unicode类型之间的差异。改变文本类型对PyQt和PySide的表现没有影响（PyQt依然正常工作，而PySide却不行）。

这是我的代码：

from PySide import QtCore
from PySide import QtGui 

#from PyQt4 import QtCore
#from PyQt4 import QtGui


class AdvComboBox(QtGui.QComboBox):
    def __init__(self, parent=None):
        super(AdvComboBox, self).__init__(parent)

        self.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.setEditable(True)

        # add a filter model to filter matching items
        self.pFilterModel = QtGui.QSortFilterProxyModel(self)
        self.pFilterModel.setFilterCaseSensitivity(QtCore.Qt.CaseInsensitive)
        self.pFilterModel.setSourceModel(self.model())

        # add a completer, which uses the filter model
        self.completer = QtGui.QCompleter(self.pFilterModel, self)
        # always show all (filtered) completions
        self.completer.setCompletionMode(QtGui.QCompleter.UnfilteredPopupCompletion)

        self.setCompleter(self.completer)

        # connect signals

        def filter(text):
            print "Edited: ", text, "type: ", type(text)
            self.pFilterModel.setFilterFixedString(str(text))

        self.lineEdit().textEdited[unicode].connect(filter)
        self.completer.activated.connect(self.on_completer_activated)

    # on selection of an item from the completer, select the corresponding item from combobox
    def on_completer_activated(self, text):
        print "activated"
        if text:
            print "text: ", text
            index = self.findText(str(text))
            print "index: ", index
            self.setCurrentIndex(index)


    # on model change, update the models of the filter and completer as well
    def setModel(self, model):
        super(AdvComboBox, self).setModel(model)
        self.pFilterModel.setSourceModel(model)
        self.completer.setModel(self.pFilterModel)


    # on model column change, update the model column of the filter and completer as well
    def setModelColumn(self, column):
        self.completer.setCompletionColumn(column)
        self.pFilterModel.setFilterKeyColumn(column)
        super(AdvComboBox, self).setModelColumn(column)


if __name__ == "__main__":
    import sys

    app = QtGui.QApplication(sys.argv)

    combo = AdvComboBox()

    names = ['bob', 'fred', 'bobby', 'frederick', 'charles', 'charlie', 'rob']

    # fill the standard model of the combobox
    combo.addItems(names)
    combo.setModelColumn(0)
    combo.resize(300, 40)
    combo.show()

    sys.exit(app.exec_())

Answer 1

我在写问题的时候自己搞明白了...

看起来虽然PySide QCompleter 的文档提到可以用一个模型和父级来初始化 QCompleter，但实际上这个方法并没有奏效。

解决办法是，在初始化完成后再设置 completer 的模型。

以下是可以正常工作的代码：

from PySide import QtCore
from PySide import QtGui 


class AdvComboBox(QtGui.QComboBox):
    def __init__(self, parent=None):
        super(AdvComboBox, self).__init__(parent)

        self.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.setEditable(True)

        # add a filter model to filter matching items
        self.pFilterModel = QtGui.QSortFilterProxyModel(self)
        self.pFilterModel.setFilterCaseSensitivity(QtCore.Qt.CaseInsensitive)
        self.pFilterModel.setSourceModel(self.model())

        # add a completer
        self.completer = QtGui.QCompleter(self)
        #Set the model that the QCompleter uses
        # - in PySide doing this as a separate step worked better
        self.completer.setModel(self.pFilterModel)
        # always show all (filtered) completions
        self.completer.setCompletionMode(QtGui.QCompleter.UnfilteredPopupCompletion)

        self.setCompleter(self.completer)

        # connect signals

        def filter(text):
            print "Edited: ", text, "type: ", type(text)
            self.pFilterModel.setFilterFixedString(str(text))

        self.lineEdit().textEdited[unicode].connect(filter)
        self.completer.activated.connect(self.on_completer_activated)

    # on selection of an item from the completer, select the corresponding item from combobox
    def on_completer_activated(self, text):
        print "activated"
        if text:
            print "text: ", text
            index = self.findText(str(text))
            print "index: ", index
            self.setCurrentIndex(index)


    # on model change, update the models of the filter and completer as well
    def setModel(self, model):
        super(AdvComboBox, self).setModel(model)
        self.pFilterModel.setSourceModel(model)
        self.completer.setModel(self.pFilterModel)


    # on model column change, update the model column of the filter and completer as well
    def setModelColumn(self, column):
        self.completer.setCompletionColumn(column)
        self.pFilterModel.setFilterKeyColumn(column)
        super(AdvComboBox, self).setModelColumn(column)


if __name__ == "__main__":
    import sys

    app = QtGui.QApplication(sys.argv)

    combo = AdvComboBox()

    names = ['bob', 'fred', 'bobby', 'frederick', 'charles', 'charlie', 'rob']

    # fill the standard model of the combobox
    combo.addItems(names)
    combo.setModelColumn(0)
    combo.resize(300, 40)
    combo.show()

    sys.exit(app.exec_())