Question

我发现了一个很棒的资源here，用于构建QComboBox，该列表提供了建议的过滤列表。每次我在组合框中选择建议的选项时，“激活的”和“ currentIndexChanged”信号都会发出三次，但效果很好。行为是不同的，具体取决于是通过鼠标还是使用箭头键和回车按钮选择了该选项。

我的问题是，我该如何调试？代码中没有任何要捕捉和阻止前两个信号发出的意义。有没有一种方法可以覆盖QComboBox“已激活”信号以尝试将其捕获到行为中？还是我必须定义自己的信号并改用它？

代码如下：

import { useHistory } from `react-router`;

const Component = (props) => {
    const history = useHistory();

    /* ... */

    history.push('/');
}

您会注意到，如果您运行代码并开始在文本框中输入“ hello”，然后单击建议的“ hello world”，则#!/usr/bin/env python # -*- coding: utf-8 -*- from PySide2 import QtCore, QtGui, QtWidgets from PySide2.QtCore import Qt, QSortFilterProxyModel from PySide2.QtWidgets import QCompleter, QComboBox class ExtendedComboBox(QComboBox): def __init__(self, parent=None): super(ExtendedComboBox, self).__init__(parent) self.setFocusPolicy(Qt.StrongFocus) self.setEditable(True) # add a filter model to filter matching items self.pFilterModel = QSortFilterProxyModel(self) self.pFilterModel.setFilterCaseSensitivity(Qt.CaseInsensitive) self.pFilterModel.setSourceModel(self.model()) # add a completer, which uses the filter model self.completer = QtWidgets.QCompleter(self) self.completer.setModel(self.pFilterModel) # always show all (filtered) completions self.completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion) self.setCompleter(self.completer) # connect signals self.lineEdit().textEdited.connect(self.pFilterModel.setFilterFixedString) 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): if text: index = self.findText(text) self.setCurrentIndex(index) # self.activated.emit(self.itemText(index)) # on model change, update the models of the filter and completer as well def setModel(self, model): super(ExtendedComboBox, 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(ExtendedComboBox, self).setModelColumn(column) def change_option(text): print(text) if __name__ == "__main__": import sys from PySide2.QtWidgets import QApplication from PySide2.QtCore import QStringListModel app = QApplication(sys.argv) string_list = ['hola muchachos', 'adios amigos', 'hello world', 'good bye'] combo = ExtendedComboBox() # either fill the standard model of the combobox combo.addItems(string_list) combo.currentIndexChanged[str].connect(change_option) # or use another model #combo.setModel(QStringListModel(string_list)) combo.resize(300, 40) combo.show() sys.exit(app.exec_())信号将返回正确的“ hello world”。如果您开始输入“ hello”，但是这次使用箭头键向下滚动到“ hello world”，它将发出3次。

我已经尝试了相同想法的多个实现，但都得到了相同的结果。将模型换成新模型后，我甚至注意到未经修改的QComboBox的行为类似。

PySide2 5.6.0a1 Windows 10.0.18362内部版本18362

感谢您的光临！

Answer 1

我使用的是PySide2 5.6.0a1，因为那是Anaconda在Python 2.7环境中安装的。 @eyllanesc指出这是一个过时的版本，可能有错误。

当我在PySide2-5.13.1的Python 3.7环境中尝试相同的代码时，一切都按预期工作。

Answer 2

我没有PySide2，但是我认为大部分时间您所要做的就是用PySide2替换我的PyQt5参考-因为这是我要做的一切，目的是使您的程序从PySide2切换到PyQt5-进行了一些重组和微调，这给了我以下功能代码：

from sys import exit as sysExit

from PyQt5.QtCore import Qt, QSortFilterProxyModel, QStringListModel, pyqtSlot
from PyQt5.QtWidgets import QApplication, QWidget, QCompleter, QComboBox, QCompleter, QHBoxLayout

class ExtendedComboBox(QComboBox):
    def __init__(self):
        QComboBox.__init__(self)

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

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

        # add a completer, which uses the filter model
        self.completer = QCompleter(self)
        self.completer.setModel(self.pFilterModel)

        # always show all (filtered) completions
        self.completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion)
        self.setCompleter(self.completer)

        # connect signals
        self.lineEdit().textEdited.connect(self.pFilterModel.setFilterFixedString)
        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):
        if text:
            index = self.findText(text)
            self.setCurrentIndex(index)
            # self.activated.emit(self.itemText(index))


    # on model change, update the models of the filter and completer as well 
    def setModel(self, model):
        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)
        self.setModelColumn(column)    

class MainApp(QWidget):
    def __init__(self):
        QWidget.__init__(self)

        string_list = ['hola muchachos', 'adios amigos', 'hello world', 'good bye']

        self.combo = ExtendedComboBox()

        # either fill the standard model of the combobox
        self.combo.addItems(string_list)
        self.combo.currentIndexChanged[str].connect(self.change_option)
        # or use another model
        #combo.setModel(QStringListModel(string_list))

        self.resize(300, 100)
        self.combo.resize(300, 50)

        HBox = QHBoxLayout()
        HBox.addWidget(self.combo)

        self.setLayout(HBox)

    @pyqtSlot(str)
    def change_option(self, text):
        print(text)

if __name__ == "__main__":
    MainThred = QApplication([])

    MainGui = MainApp()
    MainGui.show()

    sysExit(MainThred.exec_())

我认为问题是您正试图将Signals / Slots与非QObject函数一起使用（aka），您的change_option函数没有直接与从QObject继承的任何东西相关联，所以我不确定它是什么还是不是这样做，但这只是一个猜测，因为我所做的只是放入一个普通的Qt结构中，并且效果很好

如何调试发出多个“激活”信号的QComboBox

2 个答案: