PySide2 Qthread 崩溃

由于 Qtcore.Signal，我想使用 PySide2 Qtcore.Qthread，但最终出现此错误： 进程已完成，退出代码为-1073740791

from PySide2.QtCore import QThread


class Thread(QThread):
    def run(self):
        print('task started')
        k = 0
        for i in range(10000):
            for j in range(5000):
                k += 1
        print('task finished')

Thread().start()

期望有这些打印但我有这个错误：

进程已完成，退出代码为-1073740791

Update:

那么，为什么这段代码也会抛出同样的错误呢？

class Thread(QThread):
    done = Signal()

    def __init__(self):
        super(Thread, self).__init__()

    def run(self):
        print('task started')
        k = 0
        for i in range(10000):
            for j in range(5000):
                k += 1
        print('task finished')
        self.done.emit()

class Widget(QtWidgets.QWidget):
    def __init__(self):
        super(Widget, self).__init__()
        btn = QtWidgets.QPushButton('test', parent=self)
        btn.clicked.connect(self.clicked)
        btn.show()

    def clicked(self):
        t = Thread()
        t.done.connect(self.done)
        t.start()

    def done(self):
        print('done')

app = QtWidgets.QApplication()
window = Widget()
window.show()
sys.exit(app.exec_())

解释

如果您在 CMD/终端中运行代码，您将收到以下错误：

QThread: Destroyed while thread is still running
Aborted (core dumped)

导致错误的原因是线程仍在运行时被销毁，因为它是局部变量，另一方面 QThread 需要事件循环才能运行

Solution

import sys
from PySide2.QtCore import QCoreApplication, QThread


class Thread(QThread):
    def run(self):
        print("task started")
        k = 0
        for i in range(10000):
            for j in range(5000):
                k += 1
        print("task finished")


if __name__ == "__main__":
    # create event loop
    app = QCoreApplication(sys.argv)

    th = Thread()
    th.start()

    th.finished.connect(QCoreApplication.quit)
    sys.exit(app.exec_())

Update:

“t”是一个局部变量，在执行 clicked 后将被消除，导致与初始代码相同的问题，解决方案是防止它立即被销毁，为此有 2 个选项：

• 创建“t”类属性

def clicked(self):
    self.t = Thread()
    self.t.done.connect(self.done)
    self.t.start()

• 将QThread存储在生命周期较长的容器中：

class Widget(QtWidgets.QWidget):
    def __init__(self):
        super(Widget, self).__init__()
        btn = QtWidgets.QPushButton('test', parent=self)
        btn.clicked.connect(self.clicked)

        self.container = []

    def clicked(self):
        t = Thread()
        t.done.connect(self.done)
        t.start()
        self.container.append(t)

    # ...

• 将其作为父级传递给“self”，但为此，线程必须允许接收，因此您必须在构造函数中实现它：

class Thread(QThread):
    done = Signal()

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

    # ...

def clicked(self):
    t = Thread(self)
    t.done.connect(self.done)
    t.start()