PyQt5 – 为有可选项目的组合框添加动作

在这篇文章中，我们将看到如何为有可选项目的组合框添加动作。默认情况下，当我们创建一个组合框时，它的项目是不可检查的，即我们可以一次选择任何一个项目，尽管我们可以通过编辑组合框的类来创建这样的组合框。下面是可检查的组合框的表现。

PyQt5 - 为有可选项目的组合框添加动作

为了做到这一点，我们必须创建一个新的可编辑的组合框类，它继承了组合框，并增加了一个可检查的组合框的新特性。下面是新类的语法，当组合框被选中时必须添加一个方法。

# new check-able combo box
class CheckableComboBox(QComboBox):

    # constructor
    def __init__(self, parent=None):
        super(CheckableComboBox, self).__init__(parent)
        self.view().pressed.connect(self.handleItemPressed)
        self.setModel(QStandardItemModel(self))

    count = 0
    # action called when item get checked
    def do_action(self):

        window.label.setText("Checked number : " +str(self.count))

    # when any item get pressed
    def handleItemPressed(self, index):

        # getting the item
        item = self.model().itemFromIndex(index)

        # checking if item is checked
        if item.checkState() == Qt.Checked:

            # making it unchecked
            item.setCheckState(Qt.Unchecked)

        # if not checked
        else:
            # making the item checked
            item.setCheckState(Qt.Checked)

            self.count += 1

            # call the action
            self.do_action()

以下是实施情况

# importing libraries
from PyQt5.QtWidgets import * 
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * 
from PyQt5.QtCore import * 
import sys
  
  
# new check-able combo box
class CheckableComboBox(QComboBox):
  
    # constructor
    def __init__(self, parent = None):
        super(CheckableComboBox, self).__init__(parent)
        self.view().pressed.connect(self.handleItemPressed)
        self.setModel(QStandardItemModel(self))
  
    count = 0
    # action called when item get checked
    def do_action(self):
  
        window.label.setText("Checked number : " +str(self.count))
  
    # when any item get pressed
    def handleItemPressed(self, index):
  
        # getting the item
        item = self.model().itemFromIndex(index)
  
        # checking if item is checked
        if item.checkState() == Qt.Checked:
  
            # making it unchecked
            item.setCheckState(Qt.Unchecked)
  
        # if not checked
        else:
            # making the item checked
            item.setCheckState(Qt.Checked)
  
            self.count += 1
  
            # call the action
            self.do_action()
  
  
  
class Window(QMainWindow):
  
    def __init__(self):
        super().__init__()
  
        # setting title
        self.setWindowTitle("Python ")
  
        # setting geometry
        self.setGeometry(100, 100, 600, 400)
  
        # calling method
        self.UiComponents()
  
        # showing all the widgets
        self.show()
  
    # method for widgets
    def UiComponents(self):
        # creating a check-able combo box object
        self.combo_box = CheckableComboBox(self)
  
        # setting geometry of combo box
        self.combo_box.setGeometry(200, 150, 150, 30)
  
        # geek list
        geek_list = ["Sayian", "Super Sayian", "Super Sayian 2", "Super Sayian B"]
  
        # adding list of items to combo box
        self.combo_box.addItems(geek_list)
  
        # create label to show to text
        self.label = QLabel("Not checked", self)
  
        # setting geometry of label
        self.label.setGeometry(200, 100, 200, 30)
  
  
  
# create pyqt5 app
App = QApplication(sys.argv)
  
# create the instance of our Window
window = Window()
  
window.show()
  
# start the app
sys.exit(App.exec())