定时器QTimer

1 importsys
2 from PyQt5.QtCore importQTimer, Qt
3 from PyQt5.QtWidgets importQApplication, QWidget, QPushButton, QLabel, QVBoxLayout
4 
5 classDemo(QWidget):
6     def __init__(self):
7         super(Demo, self).__init__()
8         self.label = QLabel('0', self)
9 self.label.setAlignment(Qt.AlignCenter)
10 
11         self.step =0
12 
13         self.timer = QTimer(self)  #实例化定时器
14         self.timer.timeout.connect(self.update_func)  #设置定时执行的函数
15 
16         self.ss_button = QPushButton('Start', self)
17 self.ss_button.clicked.connect(self.start_stop_func)
18 
19         self.v_layout =QVBoxLayout()
20 self.v_layout.addWidget(self.label)
21 self.v_layout.addWidget(self.ss_button)
22 
23 self.setLayout(self.v_layout)
24 
25     defstart_stop_func(self):
26         if notself.timer.isActive():
27             #self.timer.isActive()  返回定时器是否激活  Ture激活
28             self.ss_button.setText('Stop')
29             self.timer.start(100)    #启动定时器，时间间隔100毫秒
30         else:
31             self.ss_button.setText('Start')
32             self.timer.stop()   #停止定时器
33 
34     defupdate_func(self):
35         self.step += 1
36 self.label.setText(str(self.step))
37 
38 
39 if __name__ == '__main__':
40     app =QApplication(sys.argv)
41     demo =Demo()
42 demo.show()
43     sys.exit(app.exec_())