这是一个关于如何实现它的简短示例.如果您希望我添加注释，请告诉我.

This is a short example of how you can implement it. Please let me know if you want me to add notes.

from PyQt5 import QtWidgets, QtCore


class WorkerThread(QtCore.QThread):
    is_active = True
    
    def run(self):
        while self.is_active:
            print("Processing...")
            self.sleep(1)


class Window(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)
        
        self.start_button = QtWidgets.QPushButton("Start")
        self.cancel_button = QtWidgets.QPushButton("Cancel")
        
        self.start_button.clicked.connect(self.start)
        self.cancel_button.clicked.connect(self.stop)
        
        laytout = QtWidgets.QVBoxLayout()
        laytout.addWidget(self.start_button)
        laytout.addWidget(self.cancel_button)
        self.setLayout(laytout)
        
        self.worker = WorkerThread()
    
    def start(self):
        self.worker.is_active = True
        self.worker.start()
        
    def stop(self):
        self.worker.is_active = False

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