python - 我在 pyqt5 中遇到错误，同时连接按钮

Question

我是第一次使用 pyqt5。从 QT 设计器创建 UI，然后将 UI 文件转换为 python 文件后，我收到错误，奇怪的部分是有时当我尝试从 Designer 重新创建 UI 时我没有收到错误，但有时会出现相同的错误逐行代码，我得到这个错误。也许我在qt设计器中做错了什么，我不知道是什么问题。

QObject::connect: 无法将 QPushButton::clicked(bool) 连接到 (null)::browse_slot()

TypeError: connect() 在 clicked(bool) 和 browse_slot() 之间失败

我的代码：

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(640, 480)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(280, 200, 89, 25))
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 640, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.retranslateUi(MainWindow)
        self.pushButton.clicked.connect(self.browse_slot)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton.setText(_translate("MainWindow", "PushButton"))

    @QtCore.pyqtSlot( )
    def browse_slot( self ):
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.DontUseNativeDialog
        fileName, _ = QtWidgets.QFileDialog.getOpenFileName(
                        None,
                        "QFileDialog.getOpenFileName()",
                        "",
                        "All Files (*);;Python Files (*.py)",
                        options=options)
        if fileName:
            self.debugPrint( "setting file name: " + fileName )
            self.model.setFileName( fileName )
            self.refreshAll()

if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    Window = QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(Window)
    Window.show()
    sys.exit(app.exec_())

标签： pythonpython-3.xpyqtpyqt5

Answer 1

如果您想使用 @QtCore.pyqtSlot() 进行连接，则必须在继承自 QObject 的类中使用它，另一方面，PyQt 文档表明建议您创建一个继承自相应小部件的类，在这种情况下 QMainWindow 并且您将类用作接口，这也解决了第一点，因为 QMainWindow 继承自 QObject。

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(640, 480)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(280, 200, 89, 25))
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 640, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton.setText(_translate("MainWindow", "PushButton"))

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.setupUi(self)
        self.pushButton.clicked.connect(self.browse_slot)

    @QtCore.pyqtSlot()
    def browse_slot(self):
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.DontUseNativeDialog
        fileName, _ = QtWidgets.QFileDialog.getOpenFileName(
                        None,
                        "QFileDialog.getOpenFileName()",
                        "",
                        "All Files (*);;Python Files (*.py)",
                        options=options)
        if fileName:
            self.debugPrint( "setting file name: " + fileName )
            self.model.setFileName( fileName )
            self.refreshAll()

if __name__ == "__main__":
    import sys
    app =QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())