pyqt 多线程出现问题

import time

from PyQt5.Qt import *


class WorkThread(QThread):
    finished=pyqtSignal()
    def __init__(self):
        super(WorkThread, self).__init__()
        self.is_running = None

    def run(self):
        print('running')
        self.is_running = True
        while self.is_running:
            print('working....')
            time.sleep(1)
            self.finished.emit()

    def stop(self):
        self.is_running = False



class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.resize(600,500)
        self.work = WorkThread()
        self.work.setParent(self)
        self.work.destroyed.connect(lambda :print('thread is destoryed'))

        self.btn = QPushButton("start")
        self.btn2 = QPushButton("stop")

        layout = QVBoxLayout()
        layout.addWidget(self.btn)
        layout.addWidget(self.btn2)

        central_widget = QWidget()
        central_widget.setLayout(layout)

        self.setCentralWidget(central_widget)

        #slots
        self.btn.clicked.connect(self.start_thread)
        self.btn2.clicked.connect(self.stop_thread)

    def start_thread(self):
        self.work.start()

    def stop_thread(self):
        self.work.stop()

    def closeEvent(self, event) -> None:
        self.work.stop()

  

在运行时关闭窗口时会出错的原因是，当关闭窗口时，工作线程仍然在运行，并且在调用`self.work.stop()`时，工作线程已经被销毁，但是在`stop()`方法中仍然尝试设置`self.is_running`为False，这会导致AttributeError。

为了解决这个问题，你可以在关闭窗口时先停止工作线程，然后再关闭窗口。你可以在`closeEvent`方法中添加一个判断，如果工作线程正在运行，则先停止工作线程，然后再关闭窗口。代码如下：

```python
def closeEvent(self, event):
    if self.work.isRunning():
        self.work.stop()
        self.work.wait()  # 等待工作线程结束
    event.accept()
```

这样，当关闭窗口时，会先停止工作线程并等待其结束，然后再关闭窗口，避免了出错的情况。

正确代码如下：

import time

from PyQt5.Qt import *


class WorkThread(QThread):

    def __init__(self):
        super(WorkThread, self).__init__()
        self.is_running = None

    def run(self):
        print('running')
        self.is_running = True
        while self.is_running:
            print('working....')
            time.sleep(1)
          

    def stop(self):
        self.is_running = False



class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.resize(600,500)
        self.work = WorkThread()
        self.work.setParent(self)
        self.work.destroyed.connect(lambda :print('thread is destoryed'))

        self.btn = QPushButton("start")
        self.btn2 = QPushButton("stop")

        layout = QVBoxLayout()
        layout.addWidget(self.btn)
        layout.addWidget(self.btn2)

        central_widget = QWidget()
        central_widget.setLayout(layout)

        self.setCentralWidget(central_widget)

        #slots
        self.btn.clicked.connect(self.start_thread)
        self.btn2.clicked.connect(self.stop_thread)

    def start_thread(self):
        self.work.start()

    def stop_thread(self):
        self.work.stop()

    def closeEvent(self, event) -> None:
        if self.work.isRunning():
            self.work.stop()
            self.work.wait()
            event.accept()

import time

from PyQt5.Qt import *
import time

qum_1 = QMutex()
class Thread_1(QThread):

    def __init__(self):
        super(Thread_1, self).__init__()

    def run(self):
        qum_1.lock()
        values=[1,2,3,4,5]
        for i in values:
            print(i)
            time.sleep(0.5)
        qum_1.unlock()


class Thread_2(QThread):
    _signal = pyqtSignal()

    def __init__(self):
        super(Thread_2, self).__init__()

    def run(self):
        values = ["a","b","c","d","e"]
        for i in values:
            print(i)
            time.sleep(1)
        self._signal.emit()






class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("的学习")
        self.resize(500,500)
        self.setup_ui()

        self.t=Thread_1()
        self.t2=Thread_2()
        self.t2._signal.connect(lambda :self.btn2.setEnabled(True))


    def setup_ui(self):

        self.btn = QPushButton('btn1',self)
        self.btn.move(10,20)
        self.btn.clicked.connect(self.btn_click)

        self.btn2 = QPushButton('btn2',self)
        self.btn.move(10,80)
        self.btn2.clicked.connect(self.btn2_click)


    def btn_click(self):
        self.t.start()

    def btn2_click(self):
        self.btn2.setEnabled(False)
        self.t2.start()





if __name__ == '__main__':
    import sys
    app=QApplication(sys.argv)

    win=Window()
    win.show()
    sys.exit(app.exec_())

import threading
import time


class Task(threading.Thread):
    def __init__(self):
        super(Task, self).__init__()

        self._stop_event = threading.Event()

    def run(self):
        while not self._stop_event.is_set():
            print('hello')

    def stop(self):
        self._stop_event.set()


t=Task()
t.start()
time.sleep(5)
t.stop()