使用 for 循环生成的多个 QProcess 终止 QThread

Question

我最近问了一个关于如何防止 QThread 在通过使用嵌套循环生成运行多个 QProcess 实例时冻结我的 GUI。提供的解决方案非常有效！我能够完成我的程序，并且运行顺利！我最近添加了一项功能，允许用户在此过程中的任何时候停止 QThread。停止功能的工作原理是没有调用 QProcesse 的新实例；然而，仍有许多未完成的 QProcess 实例仍在处理中。有没有办法确定何时不再有 QProcess 运行的任何实例并通知用户？我熟悉 QProcess 方法 waitForFinished()，但我不确定如何将其应用于使用嵌套循环生成的 QProcess 的多个实例。

这是模拟我的实际程序的数据处理方面的代码示例：

# This Python file uses the following encoding: utf-8
import sys
import os
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
import test
import time

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.ui=test.Ui_test()
        self.ui.setupUi(self)
        self.ui.pushButton_startThread.clicked.connect(self.startTestThread)
        self.ui.pushButton_Update.clicked.connect(self.stopThread)

    def startTestThread(self):
        self.xValue = self.ui.lineEdit_x.text() #Represents number of batches
        self.yValue = self.ui.lineEdit_y.text() #Represents number of images per batch
        self.runTest = testThread(self.xValue, self.yValue, self)  # Creates an instance of testThread
        self.runTest.start()  # Starts the instance of testThread

    def stopThread(self):
        self.runTest.stop()
        self.ui.lineEdit_x.setText("")
        self.ui.lineEdit_y.setText("")



class testThread(QThread):
    def __init__(self, xValue, yValue, parent=None):
        super().__init__(parent)
        self.xValue = xValue
        self.yValue = yValue

    def __del__(self):
        self.wait()

    def run(self):
        processd = []
        for x in range(int(self.xValue)):  # For loop to iterate througeach batch
            pass
            for y in range(
                int(self.yValue)):  # For loop to iterate through each image in each batch
                time.sleep(.1)
            QProcess.startDetached(os.path.dirname(os.path.realpath(__file__)) + r"\test.bat")  # Runs test.bat

    def stop(self):
        self.terminate()
        self.wait()
        print("\nStopping thread")


if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setStyle("Fusion")
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

test.bat

@ECHO OFF
ECHO Processing Batched Images.
TIMEOUT /T 15
ECHO Process Finished.

如前所述，停止 QThread 是有效的；但是，我希望能够确定所有 QProcess 实例何时完成。这将允许程序通知用户他们可以使用新参数重新启动进程。目前，我不得不告诉我的实验室伙伴等到没有更多的输出文件被写入，然后再尝试一组新的参数。

任何帮助将不胜感激。感谢您的宝贵时间！

Answer 1

虽然不优雅，但我想出了一种方法来确定 QProcess 的多个实例在终止 QThread 后何时完成：

我添加了一个批次计数器，每次 QProcess 实例排队时该计数器递增 1。
一旦线程被取消，就会用当前的批次计数器发出一个信号。
此信号连接到一个方法，该方法将确定 QProcess 的所有实例何时完成处理。
对于我的程序，QProcess 的每个实例都会生成一个唯一的输出文件。
使用while循环，可以确定所有QProcess实例完成的时刻。

这是代码示例：

# This Python file uses the following encoding: utf-8
import sys
import os
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
import test
import time
from glob import glob1

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.ui=test.Ui_test()
        self.ui.setupUi(self)
        self.ui.pushButton_startThread.clicked.connect(self.startTestThread)
        self.ui.pushButton_Update.clicked.connect(self.stopThread)

    def startTestThread(self):
        self.xValue = self.ui.lineEdit_x.text() #Represents number of batches
        self.yValue = self.ui.lineEdit_y.text() #Represents number of images per batch
        self.runTest = testThread(self.xValue, self.yValue, self)  # Creates an instance of testThread
        self.runTest.signals.batchesSubmitted.connect(self.testThreadFinished)
        self.runTest.start()  # Starts the instance of testThread

    def stopThread(self):
        self.runTest.stop()

    @pyqtSlot(int)    
    def testThreadFinished(self, batchesSubmitted):
        while len(glob1(outputFilePath + fileName, "*.txt")) < batchesSubmitted: #Compare the number of *.txt files in the output directory to the number of isntances of QProcess called
            time.sleep(1)
        self.ui.lineEdit_x.setText("")
        self.ui.lineEdit_y.setText("")
        print("All instance of QProcess are finished!")

class testThreadSignals(QObject):
    batchesSubmitted = pyqtSignal(int)

class testThread(QThread):
    def __init__(self, xValue, yValue, parent=None):
        super().__init__(parent)
        self.xValue = xValue
        self.yValue = yValue
        self.signals = testThreadSignals()

    def run(self):
        self.batchCounter = 0
        for x in range(int(self.xValue)):  # For loop to iterate througeach batch
            pass
            for y in range(
                int(self.yValue)):  # For loop to iterate through each image in each batch
                time.sleep(.1)
            QProcess.startDetached(os.path.dirname(os.path.realpath(__file__)) + r"\test.bat")  # Runs test.bat
            self.batchCounter += 1 #Counts the successful number *.txt files written

    @pyqtSlot(int)
    def stop(self):
        self.terminate()
        self.threadactive = False
        self.wait()
        self.signals.batchesSubmitted.emit(self.batchCounter)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setStyle("Fusion")
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

test.bat:

@ECHO OFF
ECHO Processing Batched Images.
TIMEOUT /T 15
REM write a unique text file
ECHO Process Finished.

我能够毫无问题地将上述 python 代码应用到我的程序中。

使用 for 循环生成的多个 QProcess 终止 QThread

Terminating QThread with multiple QProcess generated with for loop

qprocess

qthread

python-3.x

pyqt5