python 笔记11 退出应用程序

import sys
#带入系统
from PyQt5.QtWidgets import *



class quitapp(QMainWindow):
    def __init__(self,parent=None):
        super(quitapp,self).__init__(parent)
        #初始化
        self.setWindowTitle('退出程序')
        self.resize(600,600)

        #获取创建一个Button

        self.button1 = QPushButton("退出")
        #链接单击事件
        self.button1.clicked.connect(self.onclik)
        hlay = QHBoxLayout()
        hlay.addWidget(self.button1)
        mainfram = QWidget()
        mainfram.setLayout(hlay)
        self.setCentralWidget(mainfram)

    # 单击事件方法 自定义的槽
    def onclik(self):
        sender = self.sender()
        print(sender.text()+'!')
        app = QApplication.instance()
        app.quit()


if __name__ =="__main__":
    qapp = QApplication(sys.argv)
    main = quitapp()

    main.show()

    sys.exit(qapp.exec_())