python pyqt 判断线程是否启动

使用QThread类的isRunning()方法来判断线程是否启动。该方法返回一个布尔值，如果线程正在运行，则返回True，否则返回False。

import sys
from PyQt5.QtCore import QThread, pyqtSignal
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton

class MyThread(QThread):
    started_signal = pyqtSignal()
    finished_signal = pyqtSignal()

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

    def run(self):
        self.started_signal.emit()
        # 线程执行的任务
        self.finished_signal.emit()

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()
    def initUI(self):
        self.setGeometry(300, 300, 300, 200)
        self.setWindowTitle('判断线程是否启动')

        self.btn_start = QPushButton('启动线程', self)
        self.btn_start.move(50, 50)
        self.btn_start.clicked.connect(self.startThread)

        self.btn_check = QPushButton('检查线程状态', self)
        self.btn_check.move(150, 50)
        self.btn_check.clicked.connect(self.checkThread)

        self.thread = MyThread()
        self.thread.started_signal.connect(self.onStarted)
        self.thread.finished_signal.connect(self.onFinished)

    def startThread(self):
        self.thread.start()

    def checkThread(self):
        if self.thread.isRunning():
            print('线程正在运行')
        else:
            print('线程未启动或已结束')

    def onStarted(self):
        print('线程已启动')

    def onFinished(self):
        print('线程已结束')

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    mainWindow.show()
    sys.exit(app.exec_())