如何杀死 PyQt5 中的 QRunnable？

Posted 2023-03-30

【中文标题】如何杀死 PyQt5 中的 QRunnable？

【英文标题】：How to kill the QRunnable in PyQt5?

【发布时间】：2018-11-28 08:46:20

【问题描述】：

我有一个带有两个按钮 start 和 end 的应用程序。开始按钮将启动一个线程，该线程运行录音功能。该函数是使用sounddevice 和soundfile 库编写的。录音可以持续任意时间，用户可以随时按ctrl+c 停止。

所以，现在我想为end 按钮实现一个函数，以停止通过按下start 按钮启动的线程，或者该函数可以向线程发送ctrl+c 信号。因此，当前录制将停止。我不确定如何实现这一目标。任何帮助表示赞赏。

由两个.py组成的代码如下：

audio_record.py

import os
import signal
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import time
import queue
from PyQt5 import QtCore, QtGui, QtWidgets
import soundfile as sf
import sounddevice as sd
import mythreading


class Ui_MainWindow(object):
    def __init__(self):
        self.threadpool = QThreadPool()
        print("Multithreading with maximum %d threads" % self.threadpool.maxThreadCount())

    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(640, 480)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(280, 190, 75, 23))
        self.pushButton.setObjectName("pushButton")
        self.pushButton.clicked.connect(self.start_button_func)

        self.pushButton_1 = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_1.setGeometry(QtCore.QRect(380, 190, 75, 23))
        self.pushButton_1.setObjectName("pushButton")
        self.pushButton_1.clicked.connect(self.end_button_func)

        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 640, 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)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton.setText(_translate("MainWindow", "Start"))
        self.pushButton_1.setText(_translate("MainWindow", "End"))

    def record(self):
        self.pid = os.getpid()
        self.q = queue.Queue()
        self.s = sd.InputStream(samplerate=48000, channels=2, callback=self.callback)
        try:
            # Make sure the file is open before recording begins
            with sf.SoundFile('check.wav', mode='x', samplerate=48000, channels=2, subtype="PCM_16") as file:
                with self.s:
                    # 1 second silence before the recording begins
                    time.sleep(1)
                    print('START')
                    print('#' * 80)
                    print('press Ctrl+C to stop the recording')
                    while True:
                        file.write(self.q.get())
        except OSError:
            print('The file to be recorded already exists.')
            sys.exit(1)

    def callback(self, indata, frames, time, status):

        """
        This function is called for each audio block from the record function.
        """

        if status:
            print(status, file=sys.stderr)
        self.q.put(indata.copy())

    def start_button_func(self):
        self.worker = mythreading.Worker(self.record)
        self.threadpool.start(self.worker)

    def end_button_func(self):
        print('how to stop?')


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_())

mythreading.py如下：

from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *


class Worker(QRunnable):

    def __init__(self, fn, *args, **kwargs):
        super(Worker, self).__init__()
        self.fn = fn

    @pyqtSlot()
    def run(self):
        self.fn()

【参考方案1】：

你必须使用一个标志，在这种情况下threading.Event() 表示线程不应该再被执行。对于Ctrl + C 的情况，您必须使用QShortcut

import os
import queue
from PyQt5 import QtCore, QtGui, QtWidgets
import soundfile as sf
import sounddevice as sd
import mythreading
import threading

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(640, 480)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(280, 190, 75, 23))
        self.pushButton.setObjectName("pushButton")
        self.pushButton_1 = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_1.setGeometry(QtCore.QRect(380, 190, 75, 23))
        self.pushButton_1.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 640, 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)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton.setText(_translate("MainWindow", "Start"))
        self.pushButton_1.setText(_translate("MainWindow", "End"))


class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.setupUi(self)
        self.threadpool = QtCore.QThreadPool()
        print("Multithreading with maximum %d threads" % self.threadpool.maxThreadCount())
        self.pushButton.clicked.connect(self.start_button_func)
        self.pushButton_1.clicked.connect(self.end_button_func)
        self.event_stop = threading.Event()
        QtWidgets.QShortcut("Ctrl+C", self, activated=self.end_button_func)

    def record(self):
        self.pid = os.getpid()
        self.q = queue.Queue()
        self.s = sd.InputStream(samplerate=48000, channels=2, callback=self.callback)
        try:
            # Make sure the file is open before recording begins
            with sf.SoundFile('check.wav', mode='x', samplerate=48000, channels=2, subtype="PCM_16") as file:
                with self.s:
                    # 1 second silence before the recording begins
                    QtCore.QThread.sleep(1)
                    print('START')
                    print('#' * 80)
                    print('press Ctrl+C to stop the recording')
                    while not self.event_stop.is_set():
                        file.write(self.q.get())
                    print("STOP")
        except OSError:
            print('The file to be recorded already exists.')
            sys.exit(1)

    def callback(self, indata, frames, time, status):
        if status:
            print(status, file=sys.stderr)
        self.q.put(indata.copy())

    @QtCore.pyqtSlot()
    def start_button_func(self):
        print("start")
        self.worker = mythreading.Worker(self.record)
        self.threadpool.start(self.worker)

    @QtCore.pyqtSlot()
    def end_button_func(self):
        print('how to stop?')
        self.event_stop.set()

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

【讨论】：

@eyllansec 我已经以另一种方式实现了。但你的想法也有效。谢谢。

@eyllansec 仅供参考，在您的实施中，如果我们要录制多个文件，则录制将不起作用。我已经相应地编辑了您的代码，以便它可以工作。

@M.Denis 在你的问题中你没有指出这个要求，所以我没有修改你在那部分的逻辑。如果你想实现它，逻辑是在你刻录新文件之前删除该文件（如果它存在），或者使用修改后的名称，如some_name(1).wav

@M.Denis 如果您要修改逻辑，请不要编辑任何答案，您的案例中的修改必须以非实质性方式进行，否则您会破坏我的答案。跨度>