Question

我试图从子类中调用父类的方法。具体来说，我的父类是PySide.QtGui.QMainWindow对象，我的子类是PySide.QtGui.QWidget对象;后者被设定为前者的中心小部件。我试图将子项中的按钮连接到父类中的方法。这在过去使用self.parent().method_name对我有用，但它在下面的例子中没有用，我不明白为什么：

import sys
from PySide import QtGui, QtCore


class MainWindow(QtGui.QMainWindow):

    def __init__(self):
        super(MainWindow, self).__init__()

        self.do_something() #sanity check
        self.cw = ChildWidget()
        self.setCentralWidget(self.cw)
        self.show()

    def do_something(self):

        print 'doing something!'


class ChildWidget(QtGui.QWidget):

    def __init__(self):
        super(ChildWidget, self).__init__()

        self.button1 = QtGui.QPushButton()
        self.button1.clicked.connect(self.do_something_else)

        self.button2 = QtGui.QPushButton()
        self.button2.clicked.connect(self.parent().do_something)

        self.layout = QtGui.QVBoxLayout()
        self.layout.addWidget(self.button1)
        self.layout.addWidget(self.button2)
        self.setLayout(self.layout)
        self.show()

    def do_something_else(self):

        print 'doing something else!'


def main():
    app = QtGui.QApplication(sys.argv)
    ex = MainWindow()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

这是错误：

self.button2.clicked.connect(self.parent().do_something)
AttributeError: 'NoneType' object has no attribute 'do_something'

Answer 1

您从未将MainWindow设为ChildWidget的父级。因此self.parent()评估为None，因此没有函数do_something。

尝试：

import sys
from PySide import QtGui, QtCore


class MainWindow(QtGui.QMainWindow):

    def __init__(self):
        super(MainWindow, self).__init__()

        self.do_something() #sanity check
        self.cw = ChildWidget(self)
        self.setCentralWidget(self.cw)
        self.show()

    def do_something(self):

        print 'doing something!'


class ChildWidget(QtGui.QWidget):

    def __init__(self, parent):
        super(ChildWidget, self).__init__(parent)

        self.button1 = QtGui.QPushButton()
        self.button1.clicked.connect(self.do_something_else)

        self.button2 = QtGui.QPushButton()
        self.button2.clicked.connect(self.parent().do_something)

        self.layout = QtGui.QVBoxLayout()
        self.layout.addWidget(self.button1)
        self.layout.addWidget(self.button2)
        self.setLayout(self.layout)
        self.show()

    def do_something_else(self):

        print 'doing something else!'


def main():
    app = QtGui.QApplication(sys.argv)
    ex = MainWindow()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 2

这是工作代码：

import sys
from PySide import QtGui, QtCore


class MainWindow(QtGui.QMainWindow):

    def __init__(self):
        super(MainWindow, self).__init__()

        self.do_something() #sanity check
        self.cw = ChildWidget(self)
        self.setCentralWidget(self.cw)
        self.show()

    def do_something(self):

        print 'doing something!'


class ChildWidget(QtGui.QWidget):

    def __init__(self, parent=None):
        super(ChildWidget, self).__init__(parent=parent)

        self.button1 = QtGui.QPushButton()
        self.button1.clicked.connect(self.do_something_else)

        self.button2 = QtGui.QPushButton()
        self.button2.clicked.connect(self.parent().do_something)

        self.layout = QtGui.QVBoxLayout()
        self.layout.addWidget(self.button1)
        self.layout.addWidget(self.button2)
        self.setLayout(self.layout)
        self.show()

    def do_something_else(self):

        print 'doing something else!'


def main():
    app = QtGui.QApplication(sys.argv)
    ex = MainWindow()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

希望，可以帮到你。

从pyside / pyqt中的子窗口小部件调用父方法

2 个答案: