PyQt5 信号和槽

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.resize(600,400)
        self.setWindowTitle(‘title‘)
        # 实例化QPushButton对象
        self.button = QPushButton(‘Start‘, self)
        # 连接信号和槽
        self.button.clicked.connect(self.change_text)
        self.show()

    def change_text(self):
        if self.button.text() == ‘Start‘:
            self.button.setText(‘Stop‘)
        else:
            self.button.setText(‘Start‘)

if __name__ == ‘__main__‘:
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())