主页 / 问题 / 1499610
Accepted
Alexey
Asked:2023-02-24 23:25:29 +0000 UTC2023-02-24 23:25:29 +0000 UTC

流和信号

  • 772

有以下代码：

import time
import sys

#from PyQt6.QtWidgets import (
from PyQt5.QtWidgets import (
    QApplication,
    QPushButton,
    QTextEdit, 
    QVBoxLayout,
    QWidget
)

from threading import Thread


class Window(QWidget):

    def __init__(self):
        super().__init__()
   
        mainLayout = QVBoxLayout()
        self.output = QTextEdit()
        self.output.setReadOnly(True)
        mainLayout.addWidget(self.output)

        self.startButton = QPushButton("Start")
        self.startButton.clicked.connect(self.start)
        mainLayout.addWidget(self.startButton)
        self.setLayout(mainLayout)

    def task(self):
        while True:
            obj = Actions()
            obj.do()
            time.sleep(3)
            
    def start(self):
        t1 = Thread(target=self.task)
        t1.start()



class Actions():
    
    def do(self):
        window.output.append("...")   


if __name__ == "__main__":
    app = QApplication([])
    window = Window()
    window.show()
    sys.exit(app.exec())

执行此示例时（针对PyQt5）我收到以下计划的警告：

QObject::connect：无法对类型为“QTextCursor”的参数进行排队（确保使用 qRegisterMetaType() 注册了“QTextCursor”。）

在这里和这里它说：

  • 您无法与其他线程中的小部件交互，因此会显示此警告
  • 当一个线程需要改变窗口中的某些东西时，它向主线程发送一个信号，主线程中的处理程序执行必要的改变

如何落实第二点？有没有关于这个主题的例子的好教程？

先感谢您！

python

1 个回答

  1. Best Answer

    您不需要额外的库来组织流工作。

    阅读信号和插槽

    我们研究了3 种不同的简单方法来处理流。

    import sys
#import time
#from threading import Thread
#from PyQt6.QtWidgets import (
from PyQt5.QtWidgets import ( QApplication, QPushButton,
    QTextEdit, QVBoxLayout, QWidget)
from PyQt5.QtCore import QThread, pyqtSignal                          # +++


# +++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
class Thread(QThread):
    dateSignal = pyqtSignal(str)                                      # +++
    
    def __init__(self):    
        super().__init__()
        self.num = 1
        
    def run(self):        
        while True:
        
            # тут вы выполняете какие-то длительные действия
            text = f'... {self.num}'
            
            # тут вы испускаете сигнал и передаете какие-то данные
            self.dateSignal.emit(text)                                # +++
            #           2000 мс
            self.msleep(2000) 
            self.num += 1            
# +++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


class Window(QWidget):
    def __init__(self):
        super().__init__()

        self.output = QTextEdit()
        self.output.setReadOnly(True)

        self.startButton = QPushButton("Start")
        self.startButton.clicked.connect(self.start)
        
        mainLayout = QVBoxLayout(self)
        mainLayout.addWidget(self.output)        
        mainLayout.addWidget(self.startButton)
        
        self.thread = Thread()                                     # +++
        self.thread.dateSignal.connect(self.update_data)           # +++

    def start(self):
#-        t1 = Thread(target=self.task)
#-        t1.start()
        self.thread.start()                                        # +++

# +++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
    def update_data (self, text):                                  # +++
        self.output.append(text) 
# +++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


'''
    def task(self):
        while True:
            obj = Actions()
            obj.do()
            time.sleep(3)
            
    def start(self):
        t1 = Thread(target=self.task)
        t1.start()

class Actions():
    
    def do(self):
        window.output.append("...")   
'''            

if __name__ == "__main__":
    app = QApplication([])
    window = Window()
    window.show()
    sys.exit(app.exec())

    在此处输入图像描述

    • 1

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