PyQt5 – 为关闭状态的组合框添加边框

在这篇文章中，我们将看到如何在组合框处于关闭状态时为其添加边框。关闭状态基本上是指组合框的列表视图没有打开时。这个自定义的边框只在组合框处于关闭状态时出现。

为了做到这一点，我们必须改变与组合框相关的样式表，下面是样式表的代码

QComboBox::!on
{
border : 3px solid blue;
}

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
  
  
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 combo box widget
        self.combo_box = QComboBox(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)
  
        # editing style sheet code of combo box
        # adding border to the combo box when it is in off state
        self.combo_box.setStyleSheet("QComboBox::! on"
                                     "{"
                                     "border : 3px solid blue;"
                                     "}")
  
  
# create pyqt5 app
App = QApplication(sys.argv)
  
# create the instance of our Window
window = Window()
  
# start the app
sys.exit(App.exec())