pyqt5实现打开子窗口

# -*- coding: utf-8 -*-import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *class FirstWindow(QWidget): close_signal = pyqtSignal()
def __init__(self, parent=None):
# super这个用法是调用父类的构造函数
# parent=None表示默认没有父Widget，如果指定父亲Widget，则调用之
super(FirstWindow, self).__init__(parent)
self.resize(100, 100)
self.btn = QToolButton(self)
self.btn.setText("click") def closeEvent(self, event):
self.close_signal.emit()
self.close()class SecondWindow(QWidget):
def __init__(self, parent=None):
super(SecondWindow, self).__init__(parent)
self.resize(200, 200)
self.setStyleSheet("background: black") def handle_click(self):
if not self.isVisible():
self.show() def handle_close(self):
self.close()if __name__ == "__main__":
App = QApplication(sys.argv)
ex = FirstWindow()
s = SecondWindow()
ex.btn.clicked.connect(s.handle_click)
ex.btn.clicked.connect(ex.hide)
ex.close_signal.connect(ex.close)
ex.show()
sys.exit(App.exec_())