在 PyQt5 中使用 QTime 的定时器

Question

I used this code to manage a countdown using PyQt5. code -

import time
import serial
from PyQt5 import QtCore
argument = serial.Serial('COM5',9600)
countDown = 9999

def timerEvent():

    global time
    time = time.addSecs(-1)
    global argument
    global new
     
    data = time.toString("mmss")

    print(data)
    argument.write(data.encode());
    if data == '0000':
        argument.close()
        timer.stop()

    global countDown

    countDown = data


        



   
time.sleep(2);

app = QtCore.QCoreApplication(sys.argv)

timer = QtCore.QTimer()
time = QtCore.QTime(0, 1,0)

timer.timeout.connect(timerEvent)
timer.start(200)

But i want is i will input the minute and increment value using a GUI.But, can not implement. Any suggestions how can i implement that? heres my GUI

I created a new self function under class Ui_Mainwindow that connects the button to implement timer. However, it always says self error. i know how to get the lineEdit values but when i want to put it in

line 38 time = QtCore.QTime(0, 1,0) it shows self error. again the line no 40 timer.timeout.connect(timerEvent) timerevent shows error.

any idea how to implement using the GUI? Sorry for my poor explanation. is there any other way to do this?

heres the code, i just tried to do similar like base code mentioned above.

import time



countDown = 9999

from PyQt5 import QtCore, QtGui, QtWidgets

inc = 9999
newTime = 9999

class Ui_MainWindow(object):

    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.groupBox = QtWidgets.QGroupBox(self.centralwidget)
        self.groupBox.setGeometry(QtCore.QRect(70, 180, 131, 121))
        self.groupBox.setTitle("")
        self.groupBox.setObjectName("groupBox")
        self.label_2 = QtWidgets.QLabel(self.groupBox)
        self.label_2.setGeometry(QtCore.QRect(6, 50, 51, 20))
        self.label_2.setObjectName("label_2")
        self.lineEdit_Time = QtWidgets.QLineEdit(self.groupBox)
        self.lineEdit_Time.setGeometry(QtCore.QRect(60, 20, 61, 20))
        self.lineEdit_Time.setObjectName("lineEdit_Time")
        self.lineEdit_Increment = QtWidgets.QLineEdit(self.groupBox)
        self.lineEdit_Increment.setGeometry(QtCore.QRect(60, 50, 61, 20))
        self.lineEdit_Increment.setObjectName("lineEdit_Increment")
        self.pushButton_Start = QtWidgets.QPushButton(self.groupBox)
        self.pushButton_Start.setGeometry(QtCore.QRect(10, 90, 111, 23))
        self.pushButton_Start.setObjectName("pushButton_Start")
        self.label = QtWidgets.QLabel(self.groupBox)
        self.label.setGeometry(QtCore.QRect(10, 20, 47, 13))
        self.label.setObjectName("label")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

        self.pushButton_Start.clicked.connect(self.update)

        global inc
        inc = self.lineEdit_Time.text()
        global newTime
        newTime = self.lineEdit_Increment.text()




    def update(self):


        global time
        time = time.addSecs(-1)
        global argument
        global new
      
        data = time.toString("mmss")

        print(data)
        argument.write(data.encode());
        if data == '0000':
            
            timer.stop()

        global countDown

        countDown = data

        return time





    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label_2.setText(_translate("MainWindow", "Increment"))
        self.pushButton_Start.setText(_translate("MainWindow", "START"))
        self.label.setText(_translate("MainWindow", "Time"))



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

    global time

    timer = QtCore.QTimer()
    time = QtCore.QTime(0, inc,0)


    timer.timeout.connect(update)
    timer.start(newTime)


    MainWindow.show()
    sys.exit(app.exec_()) 

Answer 1

Something like this? You want to access your increment and start time from the text values of the self.lineEdit_Time and self.lineEdit_Increment widgets. Then you use this in a start_timer method, which you connect to the start buttons clicked signal. In the start_timer method, we create a timer which is a member of the main_window object, and this timer's timeout signal is connected to our update_clock method, which updates the countdown based on the self.increment value.

class Ui_MainWindow(object):
    #...

    self.pushButton_Start.pressed.connect(self.start_timer)


    def start_timer(self):
        self.countdown = int(self.lineEdit_Time.text())
        self.increment = int(self.lineEdit_Increment.text())
        self.countdownTimer = QtCore.QTimer()
        self.countdownTimer.timeout.connect(self.update_clock)
        self.countdownTimer.start(1000) # fires every 1000ms = 1s


    def update_clock(self):
        self.countdown -= self.increment
        #update a clock label that shows the countdown value
        self.clockLabel.setText(self.countdown)
        #or just print the vaule for now
        print(self.countdown)