PyQt6多线程实践：解决阻塞循环与优化线程管理

import sys
import time
from PyQt6.QtCore import QObject, pyqtSignal, QThread
from PyQt6.QtWidgets import QApplication, QMainWindow, QProgressBar, QPushButton

# ... (ThreadOne 和 MainWindow 类保持不变，或按需调整)

class ThreadTwo(QObject):
    finished_signal = pyqtSignal()
    progress_signal = pyqtSignal(int)

    def __init__(self):
        self.if_finished = False
        super().__init__()

    def run(self):
        i = 0
        while True:
            # 强制处理当前线程的事件，包括接收到的信号
            QApplication.processEvents() 
            if self.if_finished or i == 99:
                self.progress_signal.emit(i)
                return
            i += 1
            self.progress_signal.emit(i)
            time.sleep(0.1)

    def finished(self):
        self.finished_signal.emit()

    def reset(self):
        self.if_finished = False

    def stop(self):
        print("stop")
        self.if_finished = True

# ... (MainWindow 和主程序入口保持不变)

import sys, random
from PyQt6.QtCore import QObject, pyqtSignal, QThread
from PyQt6.QtWidgets import (
    QApplication, QMainWindow, QProgressBar, QPushButton,
    QWidget, QHBoxLayout,
)

# 工作线程一：模拟耗时操作
class WorkerOne(QObject):
    finished = pyqtSignal() # 操作完成信号

    def run(self):
        # 模拟一个耗时操作，例如计算或文件读写
        delay = random.randint(25, 50)
        for i in range(100):
            QThread.msleep(delay) # 使用QThread.msleep代替time.sleep，更适合Qt事件循环
        self.finished.emit() # 操作完成后发射信号

# 工作线程二：模拟进度更新
class WorkerTwo(QObject):
    progress = pyqtSignal(int) # 进度更新信号

    def __init__(self):
        super().__init__()
        self._stopped = False # 内部停止标志

    def run(self):
        self._stopped = False # 每次运行前重置停止标志
        for i in range(1, 101):
            QThread.msleep(50) # 模拟进度更新的间隔
            if not self._stopped:
                self.progress.emit(i) # 未停止则更新进度
            else:
                self.progress.emit(100) # 停止时，将进度设置为100并退出
                break

    def stop(self):
        print('WorkerTwo received stop signal')
        self._stopped = True # 收到停止指令，设置停止标志

# 主窗口类
class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("PyQt6多线程示例")
        self.setGeometry(600, 200, 400, 50)

        # UI布局
        widget = QWidget()
        layout = QHBoxLayout(widget)
        self.btn = QPushButton("开始")
        self.bar = QProgressBar()
        layout.addWidget(self.bar)
        layout.addWidget(self.btn)
        self.setCentralWidget(widget)
        self.btn.clicked.connect(self.start)

        # 初始化线程一
        self.thread_one = QThread()
        self.worker_one = WorkerOne()
        self.worker_one.moveToThread(self.thread_one) # 将worker对象移动到新线程
        self.thread_one.started.connect(self.worker_one.run) # 线程启动时执行worker的run方法
        self.worker_one.finished.connect(self.handle_finished) # worker完成时调用处理函数

        # 初始化线程二
        self.thread_two = QThread()
        self.worker_two = WorkerTwo()
        self.worker_two.moveToThread(self.thread_two) # 将worker对象移动到新线程
        self.thread_two.started.connect(self.worker_two.run) # 线程启动时执行worker的run方法
        self.worker_two.progress.connect(self.bar.setValue) # worker更新进度时更新进度条

    def start(self):
        # 避免重复启动线程
        if not (self.thread_one.isRunning() or self.thread_two.isRunning()):
            self.bar.setValue(0) # 重置进度条
            self.thread_one.start()
            self.thread_two.start()

    def handle_finished(self):
        # WorkerOne完成后，通知WorkerTwo停止
        self.worker_two.stop()
        self.reset_threads() # 重置并清理线程

    def reset_threads(self):
        # 优雅地终止线程
        self.thread_one.quit() # 请求线程退出事件循环
        self.thread_two.quit()
        self.thread_one.wait() # 等待线程真正结束
        self.thread_two.wait()
        print("所有线程已终止。")

    def closeEvent(self, event):
        # 窗口关闭时确保线程被清理
        self.reset_threads()
        event.accept()

if __name__ == "__main__":
    app = QApplication(sys.argv)
    main_window = MainWindow()
    main_window.show()
    sys.exit(app.exec())