无法访问子 window 中的 "def" - "MainWindow object has no attribute 'updateTime' "

Question

我有一个主窗口，我在其中通过按钮调用子窗口（弹出窗口），但我无法访问 def updateTime(self)，它给我一个属性错误：

AttributeError: 'MainWindow' object has no attribute 'updateTime'

如果我去掉 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

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()

您的命名空间有误。您必须确保使用正确的命名空间，否则解释器不知道在正确的位置查找 class.

Answer 2

您的问题始于行

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

让我们解构它在做什么。

您有一个按钮 self.MyButton，它存在于 class MainWindow 的实例中（您在 main()函数)
您正在连接到按钮的clicked信号。
您连接到此信号的函数是一个 lambda 函数，它调用 class widgetWindow[=48= 中的一个函数].请注意，这与调用 class 实例的方法不同。您没有在此处实例化 class （您没有创建对象）。您是说，在 class widgetWindow 中使用方法定义 start 但使其作用于对象 self ，其中 self 是 class MainWindow.

希望您现在开始看到您所做的问题。您没有创建 widgetWindow class 的实例，而是尝试使用 widgetWindow 的方法，就好像它是 MainWindow 的方法一样。如果您仍然遇到问题（特别是如果您不清楚 class 和对象之间的区别）

因此，解决方案是创建 widgetWindow 的实例（而不是直接访问 class 的方法），并将您的按钮连接到该实例的方法。我已经修改了您的代码来执行此操作，已在下面发布。我已经评论了我已经更改的部分。如果您对我所做的有任何疑问，请告诉我。

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()

无法访问子 window 中的 "def" - "MainWindow object has no attribute 'updateTime' "

Unable to acces a "def" in a sub window - "MainWindow object has no attribute 'updateTime' "

python

pyqt

qmainwindow

qtimer