Question

我有一个MainWindow，我从按钮调用子窗口（弹出窗口），我无法访问def updateTime（self），它给了我一个属性错误：

AttributeError：＆＃39; MainWindow＆＃39;对象没有属性＆＃39; updateTime＆＃39;

如果我拿出MainWindow部分它工作正常，所以我真的不明白问题是什么。任何帮助将不胜感激。

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

CurrentTime = 0

class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.central = QtGui.QWidget(self)
        self.setCentralWidget(self.central)

        self.hboxPB = QtGui.QHBoxLayout()
        self.vboxPB = QtGui.QVBoxLayout()
        self.MyButton = QtGui.QPushButton(self.central)
        self.MyButton.setText("Push Me")
        self.hboxPB.addWidget(self.MyButton)
        self.vboxPB.addLayout(self.hboxPB)
        self.MyButton.resize(90,90)
        self.MyButton.clicked.connect(lambda: widgetWindow.start(self))

class widgetWindow(QtGui.QWidget):
    def __init__(self, parent = None):
        QtGui.QWidget.__init__(self,parent)
        super(widgetWindow, self).__init__()
        widgetWindow.start(self)

    def start(self):
        window = QtGui.QMainWindow(self)
        window.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        CentralWidget = QtGui.QWidget()
        self.timeSlider = QtGui.QSlider(QtCore.Qt.Horizontal, self)
        CentralWidgetLayout = QtGui.QHBoxLayout()
        VBox = QtGui.QVBoxLayout()
        CentralWidgetLayout.addWidget(self.timeSlider)
        VBox.addLayout(CentralWidgetLayout)
        CentralWidget.setLayout(VBox)
        window.setCentralWidget(CentralWidget)
        window.show()

        self.timer = QtCore.QTimer()
        self.timer.timeout.connect(self.updateTime)
        self.timer.start(1000)

    def updateTime(self):
        global CurrentTime
        CurrentTime = CurrentTime + 1
        self.timeSlider.setValue(CurrentTime)

def main():
    app = QtGui.QApplication(sys.argv)
    win = MainWindow()
    win.show()
    win.resize(800,450)
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 1

您的问题从第

行开始

self.MyButton.clicked.connect(lambda: widgetWindow.start(self))

让我们解构这是在做什么。

您有一个按钮self.MyButton，它存在于类MainWindow的实例中（您在main()函数中实例化该类）
您正在连接按钮的clicked信号。
您连接到此信号的功能是lambda函数，调用类widgetWindow 中的函数。请注意，这与调用类实例的方法不同。你没有在这里实例化一个类（你没有创建一个对象）。您是说，使用类start中的方法定义widgetWindow，但要使其对self对象进行操作，其中self是类MainWindow的实例

希望您现在开始看到您所做的事情的问题。您尝试使用widgetWindow中的方法，而不是创建widgetWindow类的实例，就好像它是MainWindow的方法一样。我建议在Python中阅读更多关于面向对象编程的内容，以便在遇到麻烦时（尤其是如果您不清楚类和对象之间的区别）来了解这个问题。

因此，解决方案是创建widgetWindow的实例（而不是直接访问类的方法），并将按钮连接到该实例的方法。我已修改您的代码以执行此操作，如下所示。我已经评论了我改变的部分。如果您对我所做的事情有疑问，请与我联系。

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

CurrentTime = 0

class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.central = QtGui.QWidget(self)
        self.setCentralWidget(self.central)

        self.hboxPB = QtGui.QHBoxLayout()
        self.vboxPB = QtGui.QVBoxLayout()
        self.MyButton = QtGui.QPushButton(self.central)
        self.MyButton.setText("Push Me")
        self.hboxPB.addWidget(self.MyButton)
        self.vboxPB.addLayout(self.hboxPB)
        self.MyButton.resize(90,90)

        # instantiate the widgetWindow (pass this window as the parent)
        self.widgetwindow = widgetWindow(self)
        # connect the button to the start method of this instance we created above
        self.MyButton.clicked.connect(self.widgetwindow.start)

# no need to subclass QWidget here. This is just a wrapper class to hold your main window
class widgetWindow(object):
    def __init__(self, parent = None):
        # Store the parent for use later
        self.parent = parent

    def start(self):
        # change the window parent to be the parent we stored in the __init__ method
        window = QtGui.QMainWindow(self.parent)
        window.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        # Add a signal to stop the timer when the window is destroyed
        window.destroyed.connect(self.stopTimer)
        CentralWidget = QtGui.QWidget()
        # Change the parent to be the window we just created
        self.timeSlider = QtGui.QSlider(QtCore.Qt.Horizontal, window)
        CentralWidgetLayout = QtGui.QHBoxLayout()
        VBox = QtGui.QVBoxLayout()
        CentralWidgetLayout.addWidget(self.timeSlider)
        VBox.addLayout(CentralWidgetLayout)
        CentralWidget.setLayout(VBox)
        window.setCentralWidget(CentralWidget)
        window.show()

        self.timer = QtCore.QTimer()
        self.timer.timeout.connect(self.updateTime)
        self.timer.start(1000)

    def updateTime(self):
        global CurrentTime
        CurrentTime = CurrentTime + 1
        self.timeSlider.setValue(CurrentTime)

    # Method to stop the timer once the window is destroyed
    def stopTimer(self):
        self.timer.stop()

def main():
    app = QtGui.QApplication(sys.argv)
    win = MainWindow()
    win.show()
    win.resize(800,450)
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 2

试试这个：

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

CurrentTime = 0
class widgetWindow(QtGui.QWidget):
    def __init__(self, parent = None):
        QtGui.QWidget.__init__(self,parent)
        super(widgetWindow, self).__init__()
        widgetWindow.start(self)

    def start(self):
        window = QtGui.QMainWindow(self)
        window.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        CentralWidget = QtGui.QWidget()
        self.timeSlider = QtGui.QSlider(QtCore.Qt.Horizontal, self)
        CentralWidgetLayout = QtGui.QHBoxLayout()
        VBox = QtGui.QVBoxLayout()
        CentralWidgetLayout.addWidget(self.timeSlider)
        VBox.addLayout(CentralWidgetLayout)
        CentralWidget.setLayout(VBox)
        window.setCentralWidget(CentralWidget)
        window.show()

        self.timer = QtCore.QTimer()
        self.timer.timeout.connect(self.updateTime)
        self.timer.start(1000)

    def updateTime(self):
        global CurrentTime
        CurrentTime = CurrentTime + 1
        self.timeSlider.setValue(CurrentTime)



class MainWindow(QtGui.QMainWindow,widgetWindow):#here add subclass
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.central = QtGui.QWidget(self)
        self.setCentralWidget(self.central)

        self.hboxPB = QtGui.QHBoxLayout()
        self.vboxPB = QtGui.QVBoxLayout()
        self.MyButton = QtGui.QPushButton(self.central)
        self.MyButton.setText("Push Me")
        self.hboxPB.addWidget(self.MyButton)
        self.vboxPB.addLayout(self.hboxPB)
        self.MyButton.resize(90,90)
        self.MyButton.clicked.connect(lambda: widgetWindow.start(self))



def main():
    app = QtGui.QApplication(sys.argv)
    win = MainWindow()
    win.show()
    win.resize(800,450)
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

您的命名空间错误。您必须确保使用正确的命名空间，否则解释器不知道查找该类的正确位置。

无法访问＆＃34; def＆＃34;在子窗口中 - ＆＃34; MainWindow对象没有属性＆＃39; updateTime＆＃39; ＆＃34;

2 个答案: