pyqt5 显示点击了哪个按钮

Question

我是 PyQT5 的新手，我希望有几个按钮，并让最后一个按钮处于“选中”状态。当单击另一个按钮时，前一个按钮会“未选中”，而单击的按钮会“选中”。

import sys
from PyQt5.QtWidgets import *

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.setGeometry(30, 30, 400, 200)
        self.initUI()

    def initUI(self):
        self.button1 = QPushButton(self)
        self.button1.setGeometry(40, 40, 100, 50)
        self.button1.setText("Button 1")

        self.button2 = QPushButton(self)
        self.button2.setGeometry(150, 40, 100, 50)
        self.button2.setText("Button 2")

        self.show()

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

Answer 1

基于您的代码，您可以将button1 和button2 添加到QButtonGroup，并将exclusive 属性设置为True。

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.setGeometry(30, 30, 400, 200)
        self.initUI()

    def initUI(self):
        self.button1 = QPushButton(self)
        self.button1.setGeometry(40, 40, 100, 50)
        self.button1.setText("Button 1")

        self.button2 = QPushButton(self)
        self.button2.setGeometry(150, 40, 100, 50)
        self.button2.setText("Button 2")

        self.btn_grp = QButtonGroup()
        self.btn_grp.setExclusive(True)
        self.btn_grp.addButton(self.button1)
        self.btn_grp.addButton(self.button2)

        self.btn_grp.buttonClicked.connect(self.on_click)

        self.show()

    def on_click(self, btn):
        pass # do something with the button clicked

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

在这里，我还将一个空槽连接到信号QButtonGroup.buttonClicked，每当单击组中的按钮时都会发出该信号。

要找出哪个按钮是当前选中的按钮，您可以调用方法QButtonGroup.checkedButton() 和QButtonGroup.checkedId()。前者将返回一个QButton 对象，后者将返回一个索引int，对应于按钮添加到组中的顺序。

Answer 2

您可以使用 functools partial 或 sender 方法来检查按下了哪个按钮：

import sys
from PyQt5.QtWidgets import *
from functools import partial
class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.setGeometry(30, 30, 400, 200)
        self.initUI()

    def initUI(self):
        self.button1 = QPushButton(self)
        self.button1.setGeometry(40, 40, 100, 50)
        self.button1.setText("Button 1")
        self.button1.clicked.connect(partial(self.clicked_btn, 'Button 1'))

        self.button2 = QPushButton(self)
        self.button2.setGeometry(150, 40, 100, 50)
        self.button2.setText("Button 2")
        self.button2.clicked.connect(partial(self.clicked_btn, 'Button 2'))

        self.show()

    def clicked_btn(self, value):
        print(f'{value} clicked')
        sender = self.sender()
        print(f'Sender says: {sender.text()} was clicked')

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

Answer 3

1. 通过 setCheckable(True) 使按钮可检查

2. 将按钮添加到 QButtonGroup() 中，其余按钮会自动排序：

   class Example(QWidget):
      def __init__(self):
          super().__init__()
          self.setGeometry(30, 30, 400, 200)
          self.initUI()
   
      def initUI(self):
          self.button1 = QPushButton(self)
          self.button1.setGeometry(40, 40, 100, 50)
          self.button1.setText("Button 1")
          self.button1.setCheckable(True)
          self.button2 = QPushButton(self)
          self.button2.setGeometry(150, 40, 100, 50)
          self.button2.setText("Button 2")
          self.button2.setCheckable(True)
   
          self.my_button_group = QButtonGroup()
          self.my_button_group.addButton(self.button1)
          self.my_button_group.addButton(self.button2)
   
          self.show()