PyQt 异步任务 多线程的几种方案

多线程异步线程是我们常用的，如我们在执行耗时操作，又不想卡用主程序 ；

1. QThread

   from PyQt5.QtCore import QThread, pyqtSignal
   from PyQt5.QtWidgets import QApplication, QLabel, QVBoxLayout, QWidget, QPushButton
   import time

   class WorkerThread(QThread):
   progress = pyqtSignal(int) # 定义信号
   def init(self,main_instance):
   QThread.init(self)
   self.main_instance = main_instance
   def run(self):
   for i in range(1, 101):
   self.main_instance.excuteSomeThing()
   self.progress.emit(i) # 发送信号

   class MainWindow(QWidget):
   def init(self):
   super().init()
   self.resize(800, 600)
   self.initUI()

    def initUI(self):
        self.label = QLabel("进度: 0")
        self.button = QPushButton("开始任务")
        self.button.clicked.connect(self.start_task)
   
        layout = QVBoxLayout()
        layout.addWidget(self.label)
        layout.addWidget(self.button)
        self.setLayout(layout)
    def excuteSomeThing(self):
        time.sleep(0.1)  # 模拟耗时操作
   
    def start_task(self):
        self.worker = WorkerThread(self)
        self.worker.progress.connect(self.update_label)  # 连接信号到槽函数
        self.worker.start()  # 启动线程
   
    def update_label(self, value):
        self.label.setText(f"进度: {value}")

   app = QApplication([])
   window = MainWindow()
   window.show()
   app.exec_()

子线程中回调主线程函数执行，在子线程；

2. QThreadPool

   from PyQt5.QtCore import QRunnable, QThreadPool, pyqtSignal, QObject
   from PyQt5.QtWidgets import QApplication, QLabel, QVBoxLayout, QWidget, QPushButton
   import time

   class WorkerSignals(QObject):
   progress = pyqtSignal(int)

   class Worker(QRunnable):
   def init(self):
   super().init()
   self.signals = WorkerSignals()

    def run(self):
        for i in range(1, 101):
            time.sleep(0.01)  # 模拟耗时操作
            self.signals.progress.emit(i)  # 发送信号

   class MainWindow(QWidget):
   def init(self):
   super().init()
   self.resize(800, 600)
   self.initUI()
   self.thread_pool = QThreadPool()

    def initUI(self):
        self.label = QLabel("进度: 0")
        self.button = QPushButton("开始任务")
        self.button.clicked.connect(self.start_task)
   
        layout = QVBoxLayout()
        layout.addWidget(self.label)
        layout.addWidget(self.button)
        self.setLayout(layout)
   
    def start_task(self):
        worker = Worker()
        worker.signals.progress.connect(self.update_label)
        self.thread_pool.start(worker)
   
    def update_label(self, value):
        self.label.setText(f"进度: {value}")

   app = QApplication([])
   window = MainWindow()
   window.show()
   app.exec_()

3.concurrent

from PyQt5.QtCore import pyqtSignal, QObject
from PyQt5.QtWidgets import QApplication, QLabel, QVBoxLayout, QWidget, QPushButton
from concurrent.futures import ThreadPoolExecutor
import time

class Worker(QObject):
    progress = pyqtSignal(int)

    def do_work(self):
        for i in range(1, 101):
            time.sleep(0.021)  # 模拟耗时操作
            self.progress.emit(i)

class MainWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.resize(800, 600)
        self.initUI()
        self.executor = ThreadPoolExecutor(max_workers=10)

    def initUI(self):
        self.label = QLabel("进度: 0")
        self.button = QPushButton("开始任务")
        self.button.clicked.connect(self.start_task)

        layout = QVBoxLayout()
        layout.addWidget(self.label)
        layout.addWidget(self.button)
        self.setLayout(layout)

    def start_task(self):
        self.worker = Worker()
        self.worker.progress.connect(self.update_label)
        self.executor.submit(self.worker.do_work)

    def update_label(self, value):
        self.label.setText(f"进度: {value}")

app = QApplication([])
window = MainWindow()
window.show()
app.exec_()

总结

• QThread：适合需要自定义线程逻辑的场景。
• QRunnable + QThreadPool：适合轻量级、高并发任务。
• concurrent.futures：简单结合信号与槽机制使用线程池。