在Python中线程化一个类[重复]

Question

我目前正在使用 Qt 中的 UI 在 python 中执行程序。该 UI 包括对一些数据进行编程，并在每 200 毫秒单击一次按钮后发送它们。我的问题是，如果我在主类中执行此操作，程序会完全崩溃（冻结），因此我必须在另一个类或函数中执行此操作。经过一番研究，我遇到了线程，我不知道这是否对我来说是正确的解决方案，但它应该在另一个线程（在后台）中运行我的课程，直到我按下停止按钮而不使我的主窗口崩溃.第二类需要有一个循环，直到我按下停止按钮。

这是我的代码示例：

import Panel
from PyQt5 import QtWidgets, QtCore
import sys
from threading import Thread
import threading
import time

class MainWindow(QtWidgets.QMainWindow):
      
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.ui = Panel.Ui_MainWindow()
        self.ui.setupUi(self)

        self.ui.B_START.clicked.connect(self.StartBtnClicked)
        self.ui.B_STOP.clicked.connect(self.StopBtnClicked)

        #..
        #Other connect and function
        #..

    def StartBtnClicked(self):
        global Startbtn
        Startbtn = 1
        myClassA()

    def StopBtnClicked(self):
        global Startbtn
        Startbtn = 0


class myClassA(Thread):
    def __init__(self):
        Thread.__init__(self)
        print("myClassA")
        self.daemon = True
        self.run()

    def run(self):
        while Startbtn == 1:
            print("DONE") 
            #Doing stuff
            time.sleep(0.2)
                           
if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

以及用于测试它的 UI：

from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(197, 310)
        font = QtGui.QFont()
        font.setPointSize(11)
        font.setBold(True)
        font.setWeight(75)
        MainWindow.setFont(font)
        MainWindow.setStyleSheet("background-color: rgb(252, 252, 252);\n""")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setStyleSheet("")
        self.centralwidget.setObjectName("centralwidget")
        self.B_START = QtWidgets.QPushButton(self.centralwidget)
        self.B_START.setGeometry(QtCore.QRect(50, 50, 71, 61))
        font = QtGui.QFont()
        font.setPointSize(11)
        font.setBold(True)
        font.setWeight(75)
        self.B_START.setFont(font)
        self.B_START.setFocusPolicy(QtCore.Qt.ClickFocus)
        self.B_START.setStyleSheet("background-color: rgb(65, 218, 78);\n""\n""\n""\n""")
        self.B_START.setObjectName("B_START")
        self.B_STOP = QtWidgets.QPushButton(self.centralwidget)
        self.B_STOP.setGeometry(QtCore.QRect(50, 190, 71, 61))
        font = QtGui.QFont()
        font.setPointSize(11)
        font.setBold(True)
        font.setWeight(75)
        self.B_STOP.setFont(font)
        self.B_STOP.setStyleSheet("background-color: rgb(255, 0, 0);")
        self.B_STOP.setObjectName("B_STOP")
        self.B_SET = QtWidgets.QPushButton(self.centralwidget)
        self.B_SET.setGeometry(QtCore.QRect(50, 140, 71, 23))
        font = QtGui.QFont()
        font.setPointSize(11)
        font.setBold(True)
        font.setWeight(75)
        self.B_SET.setFont(font)
        self.B_SET.setStyleSheet("background-color: rgb(255,255,255);\n""\n""border-width: 1px;\n""\n""")
        self.B_SET.setObjectName("B_SET")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 197, 26))
        font = QtGui.QFont()
        font.setPointSize(11)
        font.setBold(True)
        font.setWeight(75)
        self.menubar.setFont(font)
        self.menubar.setObjectName("menubar")
        self.menulk = QtWidgets.QMenu(self.menubar)
        font = QtGui.QFont()
        font.setPointSize(11)
        font.setBold(True)
        font.setWeight(75)
        self.menulk.setFont(font)
        self.menulk.setObjectName("menulk")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.menubar.addAction(self.menulk.menuAction())

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "Panel"))
        self.B_START.setText(_translate("MainWindow", "START"))
        self.B_STOP.setText(_translate("MainWindow", "STOP"))
        self.B_SET.setText(_translate("MainWindow", "SET"))
        self.menulk.setTitle(_translate("MainWindow", "TEST"))


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_())

您只需将其放在同一个文件中并将 ui 命名为：“Pannel.py” 我采用的解决方案是好的解决方案吗？如果是，为什么当我按开始时主窗口仍然崩溃。

Answer 1

通常你会创建一个 QObject 并将其移动到 QThread 中，以使其在另一个线程中运行，从而防止主线程冻结：

import sys
import random
import string
import datetime
from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QHBoxLayout, QWidget, QPushButton, QPlainTextEdit
from PyQt5.QtCore import pyqtSignal, pyqtSlot, QThread, QObject, QTimer


class MainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)

        self.setWindowTitle("My Awesome App")

        layout1 = QVBoxLayout()
        layout2 = QHBoxLayout()

        self.startButton = QPushButton('Start Thread 1')
        self.stopButton = QPushButton('Stop Thread 1')

        self.startButton.clicked.connect(self._startThread)
        self.stopButton.clicked.connect(self._stopThread)

        layout2.addWidget(self.startButton)
        layout2.addWidget(self.stopButton)
        layout1.addLayout( layout2 )

        self.textArea = QPlainTextEdit()
        self.textArea.setPlaceholderText("")
        layout1.addWidget(self.textArea)

        widget = QWidget()
        widget.setLayout(layout1)
        self.setCentralWidget(widget)

        # setup threads
        self._threads = []
        worker = Worker()
        self.wThread = QThread()
        self.wThread.setObjectName('worker')
        self._threads.append((self.wThread, worker))  # you need to keep track of the threads and instances.
        worker.moveToThread(self.wThread)
        worker.sendData.connect(self._showData)  # connect the signal from the thread to a function to to something with the data.
        self.wThread.started.connect(worker.start)

    def _showData(self, data):
        msg = f"[{datetime.datetime.now()}] {data}"
        self.textArea.appendPlainText(msg)

    def _startThread(self):
        self.wThread.start()

    def _stopThread(self):
        self.wThread.quit()


class Worker(QObject):
    sendData = pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__()

    @pyqtSlot()
    def start(self):
        self.timer = QTimer()
        self.timer.setInterval(200)  # 200ms!
        self.timer.setSingleShot(False)
        self.timer.timeout.connect(self.run)
        self.timer.start()

    def run(self):
        data = ''.join(random.choice(string.ascii_letters) for x in range(24))
        self.sendData.emit(data)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    app.exec_()

截图：

如您所见 +- 每 200 毫秒一个随机生成的字符串被发送回主窗口。