python-3.x - Python PyQt5：根据条件，运行 CPU 密集型 QThread

Question

我正在尝试使用 PyQt5 在单独的 QThread 中运行 CPU 密集型任务。我已经尝试了代码的几种排列，只是得到了两个不需要的结果之一。

此错误：“QThread：在线程仍在运行时被销毁”

或者 GUI 挂起，就好像单独的线程不存在一样！

我创建了一个基本示例。我如何让它像我期望的那样工作？

最重要的是，我想根据条件是否为真来运行 QThread。如果为 True，则显示允许用户取消操作的警告。如果为 False，则只运行线程。

这是代码：

from PyQt5.QtWidgets import QApplication, QWidget, QMainWindow, QPushButton, QVBoxLayout, QHBoxLayout, QMessageBox
from PyQt5.QtCore import QThread, QObject

class createMainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.setFixedSize(300, 100)
        self.setWindowTitle('Thread testing')
        self.show()


class createMainWidget(QWidget):
    def __init__(self):
        super().__init__()

        threadButton = QPushButton('Start thread!')
        threadButton.clicked.connect(self.startThread)

        layout = QVBoxLayout(self)
        layout.addWidget(threadButton)


    def startThread(self):
        thread = QThread()
        worker = createWorker()
        worker.moveToThread(thread)
        thread.started.connect(worker.run) # It's like this is invisible. It should work.

        # I want to display a warning message if a certain condition is met. If the warning is displayed, the user has the option of not continuing.
        displayMessage = True
        if displayMessage == True:
            warningMessage = QMessageBox()
            warningMessage.setIcon(QMessageBox.Warning)
            warningMessage.setWindowTitle('Warning')
            warningMessage.setText('Be warned!')
            warningMessage.setStandardButtons(QMessageBox.Ok | QMessageBox.Cancel)
            warningMessage.accepted.connect(thread.start) # Why does this destroy the QThread straight away???
            warningMessage.exec_()

        # The condition is false, therefore just start the thread.
        elif displayMessage == False:
            thread.start() # This destroys the QThread as well. Why?



class createWorker(QObject):
    def __init__(self):
        super().__init__()

    def run(self):
        print('Secondary thread working')
        i = 0
        while i < 1000000000: i += 1 # Simulate CPU intensive activity
        print('Done')


app = QApplication([])

mainWidget = createMainWidget()
mainWindow = createMainWindow()
mainWindow.setCentralWidget(mainWidget)

app.exec_()

标签： python-3.xpyqt5qthread