【PyQt5 学习记录】004：简单QThread笔记

在文本编辑框中每隔几秒添加一行文本，代码如下：

 #!/usr/bin/python3
 # -*- coding:utf-8 -*-

 import sys
 from PyQt5.QtWidgets import (QApplication,
                              QWidget,
                              QLineEdit,
                              QPushButton,
                              QTextEdit,
                              QGridLayout)
 from PyQt5.QtCore import (Qt,
                           QThread,
                           pyqtSignal,
                           pyqtSlot)

 class Window(QWidget):
     def __init__(self, parent=None):
         super(Window, self).__init__(parent, Qt.Widget)

         self.resize(460, 460)
         self.setWindowTitle("Thread Test")

         self.lineEdit = QLineEdit(self)
         self.lineEdit.setPlaceholderText("connect to...")
         self.pushButton = QPushButton(">>", self)
         self.pushButton.setFixedWidth(30)
         self.stopButton = QPushButton("×", self)
         self.stopButton.setFixedWidth(30)
         self.textEdit = QTextEdit(self)
         self.textEdit.setPlaceholderText("result...")

         grid = QGridLayout()
         grid.addWidget(self.lineEdit, 0, 0, 1, 3)
         grid.addWidget(self.pushButton, 0, 3)
         grid.addWidget(self.stopButton, 0, 4)
         grid.addWidget(self.textEdit, 1, 0, 5, 5)
         self.setLayout(grid)

         self.show()

 class Run(Window):
     sig = pyqtSignal(str)

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

         self.my_thread = None
         self.pushButton.clicked.connect(self.button)
         self.stopButton.clicked.connect(self.stop_button)

     def button(self):
         self.textEdit.clear()
         line_text = self.lineEdit.text()
         # 创建线程
         self.my_thread = MyThread()
         # 将自定义信号sig连接到MyThread.on_source函数
         self.sig.connect(self.my_thread.on_source)
         # 向MyThread.on_source函数传递line_text
         self.sig.emit(line_text)
         # 直接调用MyThread.on_source()也可以，但还是建议使用信号传递，在灵活性和性能上更佳
         # self.my_thread.on_source(line_text)
         # 将自定义信号signal连接到information()槽函数
         self.my_thread.signal.connect(self.information)
         # 启动线程
         self.my_thread.start()
         self.pushButton.setEnabled(False)

     @pyqtSlot(str)
     def information(self, info):
         # 向textEdit添加lineEdit的文本
         self.textEdit.append(info)

     def stop_button(self):
         self.pushButton.setEnabled(True)
         # 将MyThread.running设为False以停止线程
         self.my_thread.running = False

 class MyThread(QThread):
     # 自定义型号，执行run()函数时，从相关线程发射此信号
     signal = pyqtSignal(str)

     def __init__(self):
         super().__init__()
         self.source_txt = None
         self.running = True

     # 当发生QThread: Destroyed while thread is still running错误时，添加QThread.wait()
     # def __del__(self):
     #    self.wait()

     def on_source(self, line_text):
             self.source_txt = line_text

     @pyqtSlot()
     def run(self):
         while self.running:
             # 发出信号
             self.signal.emit(self.source_txt)
             # 线程休眠1秒
             self.sleep(1)

 if __name__ == "__main__":
     app = QApplication(sys.argv)
     win = Run()
     sys.exit(app.exec_())

界面如图：

当线程开始运行时，每隔1秒传递一个self.source_txt。

点击pushButton时，使按钮不可用，并启动线程，在文本编辑框内不断插入lienEdit的内容。

点击stopButton时，停止线程。