PyQt5 QCheckBox

Check Box是 PyQt5 小部件之一，用于从多个选项中选择一个或多个选项。它是一个小框，选中时会被选中，否则保持空白。使用QCheckBox class在应用程序中添加复选框。

例子：

一个要求用户选择用户知道的所有编程语言的窗口。在用户每次选择或取消选择后，消息都会更新，其中包含他/她选择的所有语言的列表，例如：“你知道 c，c++ ...”。

下面是代码：

import sys
from PyQt5 import QtCore, QtGui, QtWidgets
  
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.resize(476, 308)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
  
        # Languages are not selected initially hence initialised to zero.
        self.langs ={'c':0, 'cpp':0, 'java':0, 'python':0}
          
        # For showing message 
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(140, 80, 191, 20))
          
        self.checkBox_c = QtWidgets.QCheckBox(self.centralwidget)
        self.checkBox_c.setGeometry(QtCore.QRect(170, 120, 81, 20))
        self.checkBox_c.stateChanged.connect(self.checkedc)
          
        self.checkBox_cpp = QtWidgets.QCheckBox(self.centralwidget)
        self.checkBox_cpp.setGeometry(QtCore.QRect(170, 140, 81, 20))
        self.checkBox_cpp.stateChanged.connect(self.checkedcpp)
          
        self.checkBox_java = QtWidgets.QCheckBox(self.centralwidget)
        self.checkBox_java.setGeometry(QtCore.QRect(170, 160, 81, 20))
        self.checkBox_java.stateChanged.connect(self.checkedjava)
          
        self.checkBox_py = QtWidgets.QCheckBox(self.centralwidget)
        self.checkBox_py.setGeometry(QtCore.QRect(170, 180, 81, 20))
        self.checkBox_py.stateChanged.connect(self.checkedpy)
          
        MainWindow.setCentralWidget(self.centralwidget)
  
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
          
    def checkedc(self, checked):
        if checked:
            self.langs['c']= 1
        else:
            self.langs['c']= 0
        self.show()
  
    def checkedcpp(self, checked):
        if checked:
            self.langs['cpp']= 1
        else:
            self.langs['cpp']= 0    
        self.show()
              
    def checkedjava(self, checked):
        if checked:
            self.langs['java']= 1
        else:
            self.langs['java']= 0
        self.show()
              
    def checkedpy(self, checked):
        if checked:
            self.langs['python']= 1
        else:
            self.langs['python']= 0
        self.show()            
      
    # For showing updated list of all selected languages.         
    def show(self):
        checkedlangs =', '.join([key for key in self.langs.keys()
                                         if self.langs[key]== 1]) 
          
        # Updates message having list of all selected languages. 
        self.label.setText("You know "+checkedlangs)
      
          
    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
  
        self.label.setText(_translate("MainWindow", "Select your preferred language"))
        self.checkBox_c.setText(_translate("MainWindow", "C"))
        self.checkBox_cpp.setText(_translate("MainWindow", "C++"))
        self.checkBox_java.setText(_translate("MainWindow", "Java"))
        self.checkBox_py.setText(_translate("MainWindow", "Python"))
  
if __name__ == "__main__": 
    app = QtWidgets.QApplication(sys.argv) 
    
    MainWindow = QtWidgets.QMainWindow() 
    ui = Ui_MainWindow() 
    ui.setupUi(MainWindow) 
    MainWindow.show() 
    sys.exit(app.exec_()) 

输出：

显示用户所选语言的消息。用户每次选择或取消选择后，消息都会更新。