PySide 信号未从 QThread 对象发送到插槽

Question

我正在使用一个多线程应用程序，其中创建了一个工作线程，它发出一个信号。创建线程后，我将信号与对象插槽连接，它将执行一些操作。

问题是对象槽没有被调用，有人可以帮忙找出这段代码有什么问题吗？

import time
from PySide import QtCore
from PySide.QtCore import Slot, Signal


class Worker1(QtCore.QThread):

    task_done_signal = Signal(int)

    def __init__(self):
        super(Worker1, self).__init__()
        self._run = False

    def run(self):
        self._loop()

    def _loop(self):
        count = 0
        while self._run:
            print("running")
            count += 1
            self.task_done_signal.emit(count)

    def start(self):
        self._run = True
        super(Worker1, self).start()

    def stop(self):
        self._run = False


class Worker1Listener(QtCore.QObject):
    def __init__(self):
        super(Worker1Listener, self).__init__()

    @Slot()
    def print_task(self, val):
        print("listener: {}".format(val))


def test_signals_and_threads():

    # create the thread
    worker = Worker1()

    # create the listener
    listener = Worker1Listener()

    # connect the thread signal with the slot
    worker.task_done_signal.connect(listener.print_task)

    worker.start()

    time.sleep(5)

    worker.stop()

    time.sleep(5)


if __name__ == '__main__':
    test_signals_and_threads()

Answer 1

您的代码有几个错误：

您必须有一个事件循环，以便 Qt 处理应用程序的各个对象之间的通信，在您的情况下，您必须使用 QCoreApplication.
装饰器Slot必须将函数参数的数据类型作为参数，在您的情况下：Slot(int)
你不应该使用 time.sleep 因为它是阻塞的并且不会让事件循环完成它的工作，一个可能的解决方案是在 [= 旁边使用 QEventLoop 15=].
总是建议给一个较短的时间来进行通信，为此我们使用QThread.msleep。
当您在不同线程中的信号之间进行连接时，正确的选择是使用 Qt.QueuedConnection 选项。

import sys

from PySide import QtCore

class Worker1(QtCore.QThread):
    task_done_signal = QtCore.Signal(int)

    def __init__(self):
        super(Worker1, self).__init__()
        self._run = False

    def run(self):
        self._loop()

    def _loop(self):
        count = 0
        while self._run:
            print("running")
            count += 1
            self.task_done_signal.emit(count)
            QtCore.QThread.msleep(1)

    def start(self):
        self._run = True
        super(Worker1, self).start()

    def stop(self):
        self._run = False


class Worker1Listener(QtCore.QObject):
    @QtCore.Slot(int)
    def print_task(self, val):
        print("listener: {}".format(val))

def test_signals_and_threads():
    app = QtCore.QCoreApplication(sys.argv)
    # create the thread
    worker = Worker1()
    # create the listener
    listener = Worker1Listener()

    # connect the thread signal with the slot
    worker.task_done_signal.connect(listener.print_task, QtCore.Qt.QueuedConnection)

    worker.start()

    loop = QtCore.QEventLoop()
    QtCore.QTimer.singleShot(5000, loop.quit)
    loop.exec_()

    worker.stop()

    loop = QtCore.QEventLoop()
    QtCore.QTimer.singleShot(5000, loop.quit)
    loop.exec_()

    #sys.exit(app.exec_())

if __name__ == '__main__':
    test_signals_and_threads()

PySide 信号未从 QThread 对象发送到插槽

PySide Signals not being sent to Slot, from QThread object

python

multithreading

pyside

qt-signals

qt-slot