PyQt "Class" 对象没有属性 "widget"

Question

在PyQt中，我有一个基本的程序。它由 2 个组合框、1 个行编辑和 3 个复选框组成。我想要做的是，根据第一个组合框的项目，隐藏/显示特定的小部件。但是，我不断收到错误消息：'ExportDialog' object has no attribute 'exportSetDelimiter_lbl'. I have defined this widget above in initUI, and I run initUIininit`，所以我不确定为什么会收到此错误.这是我的代码：

from PyQt5 import QtGui, QtCore, QtWidgets
import sys

class ExportDialog(QtWidgets.QMainWindow):
    def __init__(self,imagePath):
        super(ExportDialog, self).__init__()

        self.initUI(imagePath)

        #Set The GUI Position And Size
        self.setGeometry(500, 500, 600, 450)

        #Set The GUI Title
        self.setWindowTitle("Export Deck")

        #Set The GUI Icon
        self.setWindowIcon(QtGui.QIcon('MainFlashcardAppIcon.png'))
        
    def initUI(self, PATH):
        #Create The New Deck Label
        self.exportFormat_lbl = QtWidgets.QLabel(self)
        self.exportFormat_lbl.setText("Export Format: ")
        
        exportFormat_font = QtGui.QFont()
        exportFormat_font.setPointSize(8)
        
        self.exportFormat_lbl.setFont(exportFormat_font)
        self.exportFormat_lbl.adjustSize()

        self.exportFormat_combo = QtWidgets.QComboBox()
        self.exportFormat_combo.setMinimumHeight(35)
        self.exportFormat_combo.setFixedWidth(380)

        self.exportFormat_combo.currentTextChanged.connect(self.on_combobox_changed)

        self.exportDeckName_lbl = QtWidgets.QLabel(self)
        self.exportDeckName_lbl.setText("Include: ")
        
        self.exportDeckName_lbl.setFont(exportFormat_font)
        self.exportDeckName_lbl.adjustSize()

        self.exportDeckName_combo = QtWidgets.QComboBox()
        self.exportDeckName_combo.setMinimumHeight(35)
        self.exportDeckName_combo.setFixedWidth(380)


        self.exportFormat_combo.addItem(".TXT")
        self.exportFormat_combo.addItem(".CSV")
        self.exportFormat_combo.addItem(".DB")


        self.exportSetDelimiter_lbl = QtWidgets.QLabel()
        self.exportSetDelimiter_lbl.setText("Set Delimiter (Leave blank for standard delimited):")

        self.exportSetDelimiter_txt = QtWidgets.QLineEdit()
        self.exportSetDelimiter_txt.setMaxLength(1)

        self.exportSetDelimiter = QtWidgets.QLineEdit()

        vboxExport_setDelimiter = QtWidgets.QVBoxLayout()
        vboxExport_setDelimiter.addWidget(self.exportSetDelimiter_lbl)
        vboxExport_setDelimiter.addWidget(self.exportSetDelimiter_txt)

        self.includeMedia_check = QtWidgets.QCheckBox("Include HTML and Media References")
        self.includeTags_check = QtWidgets.QCheckBox("Include Tags")

        self.includeAllSQL_check = QtWidgets.QCheckBox("Include All SQL Tables")

        self.exportFormat_combo.addItem("B3 Biology")
        self.exportFormat_combo.addItem("B2 Biology")
        self.exportFormat_combo.addItem("B1 Biology")

        self.allComboList = ["B3 Biology", "B2 Biology", "B1 Biology"]

        self.exportDeckName_combo.setCurrentIndex(self.allComboList.index(PATH))

        #Create Confirm Button
        self.confirmButton = QtWidgets.QPushButton(self)
        self.confirmButton.setText("OK")

        self.confirmButton.clicked.connect(self.createDeck)

        #Create Cancel Button
        self.cancelButton = QtWidgets.QPushButton(self)
        self.cancelButton.setText("Cancel")

        self.cancelButton.clicked.connect(self.close)

        hboxExportFormat = QtWidgets.QHBoxLayout()
        hboxExportFormat.addWidget(self.exportFormat_lbl)
        hboxExportFormat.addStretch()
        hboxExportFormat.addWidget(self.exportFormat_combo)

        hboxExportName = QtWidgets.QHBoxLayout()
        hboxExportName.addWidget(self.exportDeckName_lbl)
        hboxExportName.addStretch()
        hboxExportName.addWidget(self.exportDeckName_combo)

        hboxButtonsBottom = QtWidgets.QHBoxLayout()
        hboxButtonsBottom.addStretch()
        hboxButtonsBottom.addWidget(self.confirmButton)
        hboxButtonsBottom.addWidget(self.cancelButton)

        #Create The VBoxLayout
        mainLayout = QtWidgets.QVBoxLayout(self)
        mainLayout.addLayout(hboxExportFormat)
        mainLayout.addLayout(hboxExportName)
        mainLayout.addLayout(vboxExport_setDelimiter)
        mainLayout.addWidget(self.includeMedia_check)
        mainLayout.addWidget(self.includeTags_check)
        mainLayout.addWidget(self.includeAllSQL_check)
        mainLayout.addStretch()
        mainLayout.addLayout(hboxButtonsBottom)

    def on_combobox_changed(self, i):
        if i == ".TXT":
            self.exportSetDelimiter_lbl.show()
            self.exportSetDelimiter_txt.show()

            self.includeMedia_check.show()
            self.includeTags_check.show()

            self.includeAllSQL_check.hide()
        elif i == ".CSV":
            self.exportSetDelimiter_lbl.hide()
            self.exportSetDelimiter_txt.hide()

            self.includeMedia_check.show()
            self.includeTags_check.show()

            self.includeAllSQL_check.hide()
        elif i == ".DB":
            self.exportSetDelimiter_lbl.hide()
            self.exportSetDelimiter_txt.hide()

            self.includeMedia_check.show()
            self.includeTags_check.show()

            self.includeAllSQL_check.show()

    def createDeck(self):
        print("Exported Sucessfully")
        self.close()


#Create A Windows
app = QtWidgets.QApplication(sys.argv)

window = ExportDialog("B1 Biology")
window.show()

sys.exit(app.exec_())

这是我的第一个问题，所以如果您需要任何其他信息，我会添加。任何帮助将不胜感激。谢谢！

Answer 1

当新创建组合框时，它有一个无效的当前索引 (-1) 并且没有设置 当前文本。添加第一项后，索引会自动更新为 0，当前文本更改为该项目的文本。

在添加新项目之前，您已经连接到 currentTextChanged 信号 ，并且由于函数 currentTextChanged 假定整个 ui已经创建（包括exportSetDelimiter_lbl），你得到属性错误。

虽然信号连接的放置没有规则，但通常一个好习惯是在创建它们的函数末尾对所有连接进行分组，或者无论如何，确保所有需要的东西都按它们 uired已创建连接。

所以，只需移动initUI末尾的信号连接，一切正常。

嗯...不。因为你没有为主要 window 设置 central widget 并试图在其上设置布局（这不是允许，因为 QMainWindow 具有私有且不可访问的布局）。
添加 QWidget，调用 self.setCentralWidget(someWidget) 并为 that 小部件创建布局。

PyQt "Class" 对象没有属性 "widget"

PyQt "Class" object has no attribute "widget"

python

qt

pyqt

python-3.x

pyqt5