PySide:QMetaObject.connectSlotsByName 发出警告“没有匹配的信号..."；但仍然有效..?

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问题描述

在 Qt Designer 中，我创建了一个 QDialog 窗口并使用 pysideuic 将其编译为包含一个 setupUi 方法初始化所有GUI 元素以及我扩展以实现功能的元素，如下所示:

In Qt Designer, I created a QDialog window and used pysideuic to compile that to a base class which contains a setupUi method initialising all GUI elements and which I extend to implement the functionality, as so:

class MyDialog(QtGui.QDialog, ui_file.Ui_main_dialog):
    def __init__(self, parent=None):
        QtGui.QDialog.__init__(self, parent)
        ui_file.Ui_main_dialog.__init__(self)
        self.setupUi(self)

这个 setupUi 方法调用了 QtCore.QObject.connect 以获取我在 Qt Designer 中创建的信号槽连接，我还在其中向 GUI 添加了新槽.这些插槽在 pysideuic 生成的基类中不存在，我将它们添加到 MyDialog 类中，例如

This setupUi method has calls to QtCore.QObject.connect for the signal-slot connections I created in Qt Designer, where I also added new slots to the GUI. These slots are non-existent in the base class generated by pysideuic and I added them to the MyDialog class, e.g.

    def on_list_selection_changed(self):
        self.run_btn.setEnabled(len(self.modules_list.selectedIndexes()) > 0)

在这个例子中，槽在 Qt Designer 中被称为 on_list_selection_changed()(参数列表为空).

For this example, the slot is called on_list_selection_changed() (with empty parameter list) in Qt Designer.

在初始化时，MyDialog.__init__ 调用 Ui_main_dialog.setupUi，后者最终调用 QtCore.QMetaObject.connectSlotsByName(后两个带有 MyDialog 实例的 self 当前正在创建).这会在 sys.stderr 上发出以下行:

On initialisation, MyDialog.__init__ calls Ui_main_dialog.setupUi, which eventually calls QtCore.QMetaObject.connectSlotsByName (the latter two with the MyDialog instance's self which is currently being created). This emits the following line on sys.stderr:

QMetaObject::connectSlotsByName: No matching signal for on_list_selection_changed()

尽管如此，当连接的modules_list.itemSelectionChanged()(modules_list 是一个QListWidget)时，信号表现正确并且槽被调用.

Still, the signal behaves correctly and the slot is called when the connected modules_list.itemSelectionChanged() (modules_list is a QListWidget).

所以这是我的问题:为什么我会收到此警告?鉴于它似乎无关紧要，我该怎么做才能让它不出现?

So here is my question: why do I receive this warning? What can I do so it doesn't appear, given that it seems to be irrelevant?

编辑:由于我在过去 5 个月内没有收到任何答案，所以我想我给出了一个完整的示例，以便更容易重现问题.

Edit: Since I didn't receive any answers in the last 5 months, I thought I give a complete example to make reproducing the problem easier.

这个例子与上面的问题不同，它只使用了一个 QLineEdit 实例.代码如下:

This example differs from the question above in that it only uses a QLineEdit instance. Here is the code:

import sys
from PySide import QtCore, QtGui

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        self.lineEdit = QtGui.QLineEdit(Dialog)
        self.lineEdit.setObjectName("lineEdit")
        QtCore.QObject.connect(self.lineEdit, QtCore.SIGNAL("textChanged(QString)"), Dialog.on_lineEdit_changed)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

class MainWindow(QtGui.QMainWindow, Ui_Dialog):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        Ui_Dialog.__init__(self)
        Ui_Dialog.setupUi(self, self)
    @QtCore.Slot(unicode) # signal with no arguments
    def on_lineEdit_changed(self, text):
        print 'Changed to', text

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    mw = MainWindow()
    mw.show()
    sys.exit(app.exec_())

请注意，Ui_Dialog 类的代码是由 Qt Designer 的 .ui 文件中的 pysideuic 生成的，但我将其缩短了一点以更好地突出问题.

Note that the code for the Ui_Dialog class is generated by the pysideuic from the Qt Designer's .ui file, but I shortened it a bit to better highlight the problem.

QtCore

PySide:QMetaObject.connectSlotsByName 发出警告“没有匹配的信号..."；但仍然有效..?

问题描述

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