单选按钮QRadioButton

 1 import sys
 2 from PyQt5.QtGui import QPixmap
 3 from PyQt5.QtWidgets import QApplication, QWidget, QRadioButton, QLabel, QHBoxLayout, QVBoxLayout
 4 
 5 
 6 class Demo(QWidget):
 7     def __init__(self):
 8         super(Demo, self).__init__()
 9         self.off_button = QRadioButton('off', self)  # 实例化单选按钮，参数1：显示的文本
10         self.on_button = QRadioButton('开', self)
11 
12         self.pic_label = QLabel(self)
13 
14         self.button_h_layout = QHBoxLayout()
15         self.pic_h_layout = QHBoxLayout()
16         self.all_v_layout = QVBoxLayout()
17 
18         self.layout_init()
19         self.radiobutton_init()
20         self.label_init()
21         self.off_button.setText('关')  #设置按钮显示的文本
22         print(self.on_button.text())   #返回按钮显示的文本
23 
24     def layout_init(self):
25         self.pic_h_layout.addStretch(1)  # 在布局中添加1个占位符。参数：n个位置
26         self.pic_h_layout.addWidget(self.pic_label)
27         self.pic_h_layout.addStretch(1)
28         self.button_h_layout.addWidget(self.off_button)
29         self.button_h_layout.addWidget(self.on_button)
30         self.all_v_layout.addLayout(self.pic_h_layout)
31         self.all_v_layout.addLayout(self.button_h_layout)
32 
33         self.setLayout(self.all_v_layout)
34 
35     def radiobutton_init(self):
36         self.off_button.setChecked(True)  # 设置为选中状态
37         self.off_button.toggled.connect(self.on_off_bulb_func)  # 按钮状态发生变化时发出信号
38         # self.on_button.toggled.connect(self.on_off_bulb_func)
39 
40     def label_init(self):
41         self.pic_label.setPixmap(QPixmap('off.png'))  
42 
43     def on_off_bulb_func(self):
44         if self.off_button.isChecked():  #返回按钮是否被选中,True选中
45             self.pic_label.setPixmap(QPixmap('off.png'))   #在标签上添加一张图片
46             #需要  from PyQt5.QtGui import QPixmap
47         else:
48             self.pic_label.setPixmap(QPixmap('on.png'))
49     #图片下载地址：
50     #off.png: https://www.easyicon.net/download/png/538753/64/
51     #on.png: https://www.easyicon.net/download/png/538754/64/
52 
53 
54 if __name__ == '__main__':
55     app = QApplication(sys.argv)
56     demo = Demo()
57     demo.show()
58     sys.exit(app.exec_())