如何将动态创建的小部件绑定到 PyQt 中的信号？

Question

我有一张表，里面装满了通过按下按钮创建的组合框。我的问题是你如何找出哪个组合框发生了变化？如果它是一个固定的组合框，我会使用以下内容：

QtCore.QObject.connect(self.comboBox, QtCore.SIGNAL(_fromUtf8("currentIndexChanged(int)")), self.dosomething)

为了更清楚，我添加了下面的示例代码：

from PyQt4 import QtCore, QtGui
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import sys

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    _fromUtf8 = lambda s: s

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName(_fromUtf8("Dialog"))
        Dialog.resize(332, 122)
        Dialog.setMinimumSize(QtCore.QSize(332, 122))
        Dialog.setMaximumSize(QtCore.QSize(332, 122))
        self.tableWidget = QtGui.QTableWidget(Dialog)
        self.tableWidget.setGeometry(QtCore.QRect(10, 10, 256, 101))
        self.tableWidget.setObjectName(_fromUtf8("tableWidget"))
        self.tableWidget.setColumnCount(2)   
        item = QtGui.QTableWidgetItem()
        self.tableWidget.setHorizontalHeaderItem(0, item)
        item = QtGui.QTableWidgetItem()
        self.tableWidget.setHorizontalHeaderItem(1, item)
        self.tableWidget.setRowCount(0)
        self.layoutWidget_6 = QtGui.QWidget(Dialog)
        self.layoutWidget_6.setGeometry(QtCore.QRect(280, 30, 40, 54))
        self.layoutWidget_6.setObjectName(_fromUtf8("layoutWidget_6"))
        self.verticalLayout_2 = QtGui.QVBoxLayout(self.layoutWidget_6)
        self.verticalLayout_2.setMargin(0)
        self.verticalLayout_2.setObjectName(_fromUtf8("verticalLayout_2"))
        self.pushButton_2 = QtGui.QPushButton(self.layoutWidget_6)
        self.pushButton_2.setAutoDefault(False)
        self.pushButton_2.setObjectName(_fromUtf8("pushButton_2"))
        self.verticalLayout_2.addWidget(self.pushButton_2)
        self.pushButton = QtGui.QPushButton(self.layoutWidget_6)
        self.pushButton.setAutoDefault(False)
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.verticalLayout_2.addWidget(self.pushButton)

        QtCore.QObject.connect(self.pushButton_2, QtCore.SIGNAL(_fromUtf8("clicked()")), self.add)

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(QtGui.QApplication.translate("Dialog", "Dialog", None, QtGui.QApplication.UnicodeUTF8))
        self.pushButton_2.setText(QtGui.QApplication.translate("Dialog", "+", None, QtGui.QApplication.UnicodeUTF8))
        self.pushButton.setText(QtGui.QApplication.translate("Dialog", "-", None, QtGui.QApplication.UnicodeUTF8))
        item = self.tableWidget.horizontalHeaderItem(0)
        item.setText(QtGui.QApplication.translate("Dialog", "New Column", None, QtGui.QApplication.UnicodeUTF8))
        item = self.tableWidget.horizontalHeaderItem(1)
        item.setText(QtGui.QApplication.translate("Dialog", "New Column", None, QtGui.QApplication.UnicodeUTF8))

    def change(self):
        '''Depending on the comboBox whose index has changed,
         find the row and insert the right options in the comboBox
          in the next column'''

        #Find the row
        ins = self.tableWidget.focusWidget()
        selected_row = self.tableWidget.indexAt(ins.pos()).row()
        choice = self.tableWidget.cellWidget(0, selected_row).currentText()

        #Select the appropriate options
        if choice == 'B':
            choices_list = ['4', '5', '6']
        if choice == 'A':
            choices_list = ['1', '2', '3']

        #Set ComboBox in the next column
        comboBox = QtGui.QComboBox(self.tableWidget)
        font = QtGui.QFont()
        font.setPointSize(10)
        comboBox.setFont(font)

        for combo_ind, i in enumerate(choices_list):
            comboBox.addItem(_fromUtf8(""))
            comboBox.setItemText(combo_ind, QtGui.QApplication.translate("Dialog", i, None, QtGui.QApplication.UnicodeUTF8))

    def add(self):
        index = self.tableWidget.rowCount()
        self.tableWidget.insertRow(index)

        comboBox = QtGui.QComboBox(self.tableWidget)
        font = QtGui.QFont()
        font.setPointSize(10)
        comboBox.setFont(font)

        for combo_ind, i in enumerate(["A", "B"]):
            comboBox.addItem(_fromUtf8(""))
            comboBox.setItemText(combo_ind, QtGui.QApplication.translate("Dialog", i, None, QtGui.QApplication.UnicodeUTF8))     
        self.tableWidget.setCellWidget(index, 0, comboBox)

        comboBox = QtGui.QComboBox(self.tableWidget)
        font = QtGui.QFont()
        font.setPointSize(10)
        comboBox.setFont(font)

        #[1,2,3] is for A
        #[4,5,6] is for B
        for combo_ind, i in enumerate(['1', '2', '3']):
            comboBox.addItem(_fromUtf8(""))
            comboBox.setItemText(combo_ind, QtGui.QApplication.translate("Dialog", i, None, QtGui.QApplication.UnicodeUTF8))
        self.tableWidget.setCellWidget(index, 1, comboBox) 

app = QApplication(sys.argv)
app.setApplicationName('MyWindow')
window = QDialog()
ui = Ui_Dialog()
ui.setupUi(window)
window.show()
sys.exit(app.exec_())

Answer 1

您可能会尝试使用lambda，例如similar question。

在您的情况下，它可能类似于以下内容：

QtCore.QObject.connect(self.comboBox, QtCore.SIGNAL("currentIndexChanged(int)"), lambda index: self.dosomething(combo_id, index))

您相应地更改您的self.dosomething 方法以采用额外的参数（例如，某种ID）。这将允许您传递有关该事件的一些识别信息，即它发生在哪个组合框，作为奖励，即使添加了新组件，您也可以对所有组件重复使用一种方法。

另请注意：在您的情况下，信号正在将值（int）传递给插槽。您也需要该信息，因此您将其捕获为 lambda 的参数（在上面我称之为 index ）并将其与关于信号是哪个组合框的识别信息（ combo_id ）一起传递给您的插槽方法为了。

如果您的信号不向槽发送任何参数，例如单击按钮，则无需使用 lambda 参数，如下所示：

QtCore.QObject.connect(self.button, QtCore.SIGNAL("clicked()"), lambda: self.dosomething(button_id))

希望这会有所帮助。

Answer 2

您需要重新实现要动态创建的小部件。基本上this code 也是这个问题的答案。