如何编写一个无限循环来接收UDP数据?

2022-01-12 00:00:00 python python-3.x pyqt pyqt5 python-sockets

问题描述

我正在尝试制作一个接收 UDP 数据并使用 python (PyQt5) 在列表视图中显示数据的应用程序.当我启动接收器时，应用程序卡住并且没有响应.我怎样才能解决这个问题?请参阅下面的代码.

I'm trying to make an app that receives UDP data and shows the data in a list view using python (PyQt5). When I start the receiver, the app gets stuck and does not respond. How can I fix this? See code below. 

import sys
import os
import socket
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

class udpReceiverApp():
     app = QApplication (sys.argv)
     x = 1
     ip = "192.168.1.4"
     port =515
     server_start = True
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     sock.bind((ip,port))

     def __init__(self):
         self.w = QWidget()
         self.lbl = QLabel ("udp receiver",self.w)
         self.btn = QPushButton ("click me",self.w)
         self.lst = QListWidget(self.w)
         self.lst.resize(200,100)

         self.lbl.move(10, 90)
         self.btn.move(50, 50)
         self.lst.move(10, 90)

         self.btn.clicked.connect(self.startReceiver)

         self.w.setGeometry(300, 300, 300, 200)
         self.w.setWindowTitle("udp receive")
         self.w.show()
         sys.exit(udpReceiverApp.app.exec_())

     def addLstItem(self):
         self.lst.insertItem(0,"item"+str(udpReceiverApp.x) )
         udpReceiverApp.x +=1

     def startReceiver(self):

         while udpReceiverApp.server_start:
               data, addr = self.sock.recvfrom(1024)
               self.lst.insertItem(0,data)

udpReceiverApp()

解决方案

你不应该在主线程中有无限循环，因为它会锁定 Qt 事件循环，而应该在另一个线程中执行它并通过信号发送信息

You should not have an infinite loop in the main thread since it locks the Qt event loop, instead you should execute it in another thread and send the information through signals

import sys
import os
import socket
from PyQt5 import QtCore, QtWidgets

class UDPWorker(QtCore.QObject):
    dataChanged = QtCore.pyqtSignal(str)

    def __init__(self, parent=None):
        super(UDPWorker, self).__init__(parent)
        self.server_start = False

    @QtCore.pyqtSlot()
    def start(self):
        self.server_start = True
        ip = "192.168.1.4"
        port = 515
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.sock.bind((ip,port))
        self.process()

    def process(self):
        while self.server_start:
            data, addr = self.sock.recvfrom(1024)
            self.dataChanged.emit(str(data))

class UDPWidget(QtWidgets.QWidget):
    started = QtCore.pyqtSignal()

    def __init__(self, parent=None):
        super(UDPWidget, self).__init__(parent)
        btn = QtWidgets.QPushButton("Click Me")
        btn.clicked.connect(self.started)
        self.lst = QtWidgets.QListWidget()

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(QtWidgets.QLabel("udp receiver"))
        lay.addWidget(btn)
        lay.addWidget(self.lst)

        self.setWindowTitle("udp receive")

    @QtCore.pyqtSlot(str)
    def addItem(self, text):
        self.lst.insertItem(0, text)

if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = UDPWidget()
    worker = UDPWorker()
    thread = QtCore.QThread()
    thread.start()
    worker.moveToThread(thread)
    w.started.connect(worker.start)
    worker.dataChanged.connect(w.addItem)
    w.show()
    sys.exit(app.exec_())

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