如何编写一个无限循环来接收UDP数据？答案

【问题标题】：How to write an infinite loop for receiving UDP data?如何编写一个无限循环来接收UDP数据？
【发布时间】：2019-08-07 03:44:07
【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。

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()

【问题讨论】：

您的代码挂在data, addr = self.sock.recvfrom(1024)。解决方案：stackoverflow.com/questions/2719017/…

标签： python python-3.x pyqt pyqt5 python-sockets

【解决方案1】：

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

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_())

【讨论】：