PyQt5 QSpinBox – 阻塞信号

在本文中，我们将看到如何阻止旋转框的信号，阻塞信号意味着与旋转框连接的方法将不会接收信号，例如，当我们向其添加动作时，当其值发生变化时，该动作将不起作用。被阻塞时发出的信号不会被缓冲。

注意：即使旋转框的信号已被阻止，也会发出destroyed()信号

为了做到这一点，我们使用 blockSignals 方法。

Syntax : spin_box.blockSignals(True)

Argument : It takes bool as argument

Action Performed : It blocks the emitting signals of spin box

下面是实现

# 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 spin box
        self.spin = QSpinBox(self)
  
        # setting geometry to spin box
        self.spin.setGeometry(100, 100, 250, 40)
  
        # setting prefix to spin
        self.spin.setPrefix("Prefix ")
  
        # setting suffix to spin
        self.spin.setSuffix(" Suffix")
  
        # adding action to the spin box
        self.spin.valueChanged.connect(self.do)
  
        # blocking signals of the spin box
        self.spin.blockSignals(True)
  
        # creating a label
        self.label = QLabel("Label ", self)
  
        # setting geometry to the label
        self.label.setGeometry(100, 200, 300, 30)
  
    # method called by spin box
    def do(self):
        # setting text to the label
        self.label.setText("Action done")
  
  
# create pyqt5 app
App = QApplication(sys.argv)
  
# create the instance of our Window
window = Window()
  
# start the app
sys.exit(App.exec())

输出 ：
标签文本没有更改，因为旋转框的信号被阻止，因此它们无法调用值更改信号