从pyside/pyqt中的子窗口小部件调用父方法

Question

我正在尝试从子类中调用父类的方法.具体来说,我的父类是一个PySide.QtGui.QMainWindow对象,我的子类是一个PySide.QtGui.QWidget对象; 后者被设定为前者的中心小部件.我正在尝试将子项中的按钮连接到父类中的方法.这在过去使用过self.parent().method_name,但在下面的示例中不起作用,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

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。

Answer 2

您永远不会将自己设置为自己MainWindow的父母ChildWidget。因此self.parent()求值None因此没有功能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()