I tried to design a pyqt gui in when I press "x" will stop run function a counter , what should i do ?

I only know to use the following code

    def closeEvent(self,event):   
          pass  

Logic Code

from PyQt5 import QtWidgets, QtGui, QtCore
from PyQt5.QtCore import *
import sys
import time
from GUI import Ui_MainWindow

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self) 
        self.thread = MyThread(self)        
        self.thread.trigger.connect(self.textBrowser)
        self.thread.start()       
           
    def textBrowser(self,a):  
       self.ui.textBrowser_4.clear()           
       self.ui.textBrowser_4.append(str(a))        
     
    def closeEvent(self,event):   
          pass  
 
    
    class MyThread(QThread):
        trigger = pyqtSignal(str) 

       def run(self):
            a = 0
            while True:     
                a = a   1
                self.trigger.emit(str(a))
                time.sleep(1)
                

if __name__ == "__main__":   
    app = QtWidgets.QApplication([])
    MainWindow = MainWindow()    
    MainWindow.show()      
    sys.exit(app.exec_())

GUI Code

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
        def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(944, 587)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label_2 = QtWidgets.QLabel(self.centralwidget)
        self.label_2.setGeometry(QtCore.QRect(30, 310, 181, 41))
        self.label_2.setObjectName("label_2")
        self.label_4 = QtWidgets.QLabel(self.centralwidget)
        self.label_4.setGeometry(QtCore.QRect(30, 20, 141, 21))
        self.label_4.setObjectName("label_4")
        self.textBrowser_4 = QtWidgets.QTextBrowser(self.centralwidget)
        self.textBrowser_4.setGeometry(QtCore.QRect(230, 300, 241, 61))
        self.textBrowser_4.setObjectName("textBrowser_4")
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label_2.setText(_translate("MainWindow", "counter"))

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

CodePudding user response：

Add an initiator and an is_running variable in your Thread class like so :

def __init__(self):
    self.is_running = True
           

Then make your loop depend on the truthness of this new variable :

def run(self):
    a = 0
    while self.is_running:  
         ... your logic here

And finally when you want to exit in closeEvent() :

self.thread.is_running = False

Cheers

CodePudding user response：

If you just want to know how to stop a while loop, i think you want "break". Example code:

i = 0
while True:
    print(i)
    i  = 1 
    if i > 10:
        break

which prints:

0
1
2
3
4
5
6
7
8
9
10