您需要将主窗口作为参数传递给的构造函数
MyPopup，请尝试以下操作：
import sysfrom PyQt4.Qt import *class MyPopup(QWidget): def __init__(self, mainWindow): QWidget.__init__(self) # use the mainWindow passed as parameter mainWindow.label1.setText('hello')class MainWindow(QMainWindow): def __init__(self, *args): QMainWindow.__init__(self, *args) self.cw = QWidget(self) self.setCentralWidget(self.cw) self.btn1 = QPushButton("Click me", self.cw) self.btn1.setGeometry(QRect(50, 50, 100, 30)) self.label1 = QLabel("No Commands running", self.cw) self.connect(self.btn1, SIGNAL("clicked()"), self.doit) self.w = None def doit(self): self.w = MyPopup(self) #when creating the popup pass in the main window self.w.setGeometry(QRect(100, 100, 400, 200)) self.w.show()if __name__ == "__main__": app = QApplication(sys.argv) myapp = MainWindow() myapp.show() sys.exit(app.exec_())
