PyQt QTcpServer:如何将数据返回到多个客户端？

Question

我期待使用PyQt创建一个QTcpServer,它可以同时将数据返回给两个或更多客户端.我认为这需要线程化.

使用threadedfortuneserver.py示例作为测试用例(包含在PyQt4中,在我的系统上,它位于/ usr/share/doc/python-qt4-doc/examples/network中),我想连接多个客户端,每次都需要一个客户要求发财,其他客户也会更新一条消息,例如"客户X刚刚收到财产'等等等等等等."

我理解fortuneserver/client程序是如何工作的,但似乎在将财富发送回客户端后立即终止客户端连接.我的具体问题是:

1. 是否可以保持所有连接处于打开状态,以便每当其中一个客户端请求发财时,其他客户端都可以更新？

2. 如果是这样,跟踪和循环连接的客户端的最佳方法是什么？

这对我来说是一个严重的绊脚石,因为我想开发一个应用程序,其中几个客户端可以进行交互,并且每个客户端都可以更新其他客户端的操作.

在此先感谢您的帮助,如果我能提供任何其他信息,请与我们联系.

我找到了这个帖子,但没有足够的具体信息可供使用.关于Python套接字包的其他讨论,但我的理解是,当使用PyQt时,服务器应该是QTcpServer,所以一切都很好.

***编辑***

以下是我的解决方案的开始阶段.我创建了一个基本的服务器和客户端.服务器只是将客户输入的内容发送回"行编辑"框.

我基于使用Python和Qt的Rapid GUI Programming的第18章中的"buildingservices"示例.

我做的主要改变是现在线程无限期地运行并且它们的套接字保持打开状态,监听客户端发送的数据.

它处理多个客户端很好.这当然很难看,但我认为这是一个很好的起点.

我想要的是能够在一个客户端输入文本时通知每个客户端(比如典型的聊天程序).

另外,为了让您了解自己与谁打交道,我不是专业程序员.我是一名物理学家,拥有多年无纪律的脚本和摆弄我的腰带.但我想尝试开发可以传递数据的基本服务器/客户端程序.

感谢您的任何帮助或建议!

服务器:

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtNetwork import *

PORT = 9999
SIZEOF_UINT16 = 2

class Thread(QThread):

    #lock = QReadWriteLock()

    def __init__(self, socketId, parent):
        super(Thread, self).__init__(parent)
        self.socketId = socketId

    def run(self):
        self.socket = QTcpSocket()

        if not self.socket.setSocketDescriptor(self.socketId):
            self.emit(SIGNAL("error(int)"), socket.error())
            return

        while self.socket.state() == QAbstractSocket.ConnectedState:
            nextBlockSize = 0
            stream = QDataStream(self.socket)
            stream.setVersion(QDataStream.Qt_4_2)
            if (self.socket.waitForReadyRead(-1) and
                self.socket.bytesAvailable() >= SIZEOF_UINT16):
                nextBlockSize = stream.readUInt16()
            else:
                self.sendError("Cannot read client request")
                return
            if self.socket.bytesAvailable() < nextBlockSize:
                if (not self.socket.waitForReadyRead(-1) or
                    self.socket.bytesAvailable() < nextBlockSize):
                    self.sendError("Cannot read client data")
                    return

            textFromClient = stream.readQString()

            textToClient = "You wrote: \"{}\"".format(textFromClient)
            self.sendReply(textToClient)

    def sendError(self, msg):
        reply = QByteArray()
        stream = QDataStream(reply, QIODevice.WriteOnly)
        stream.setVersion(QDataStream.Qt_4_2)
        stream.writeUInt16(0)
        stream.writeQString("ERROR")
        stream.writeQString(msg)
        stream.device().seek(0)
        stream.writeUInt16(reply.size() - SIZEOF_UINT16)
        self.socket.write(reply)

    def sendReply(self, text):
        reply = QByteArray()
        stream = QDataStream(reply, QIODevice.WriteOnly)
        stream.setVersion(QDataStream.Qt_4_2)
        stream.writeUInt16(0)
        stream.writeQString(text)
        stream.device().seek(0)
        stream.writeUInt16(reply.size() - SIZEOF_UINT16)
        self.socket.write(reply)


class TcpServer(QTcpServer):

    def __init__(self, parent=None):
        super(TcpServer, self).__init__(parent)

    def incomingConnection(self, socketId):
        self.thread = Thread(socketId, self)
        self.thread.start()


class ServerDlg(QPushButton):

    def __init__(self, parent=None):
        super(ServerDlg, self).__init__(
                "&Close Server", parent)
        self.setWindowFlags(Qt.WindowStaysOnTopHint)

        self.tcpServer = TcpServer(self)
        if not self.tcpServer.listen(QHostAddress("0.0.0.0"), PORT):
            QMessageBox.critical(self, "Threaded Server",
                    "Failed to start server: {}".format(
                    self.tcpServer.errorString()))
            self.close()
            return

        self.connect(self, SIGNAL("clicked()"), self.close)
        font = self.font()
        font.setPointSize(24)
        self.setFont(font)
        self.setWindowTitle("Threaded Server")

app = QApplication(sys.argv)
form = ServerDlg()
form.show()
form.move(0, 0)
app.exec_()

客户:

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtNetwork import *

PORT = 9999
SIZEOF_UINT16 = 2

class Form(QDialog):

    def __init__(self, parent=None):
        super(Form, self).__init__(parent)

        # Ititialize socket
        self.socket = QTcpSocket()
        # Initialize data IO variables
        self.nextBlockSize = 0
        self.request = None
        # Create widgets/layout
        self.browser = QTextBrowser()
        self.lineedit = QLineEdit("Texty bits")
        self.lineedit.selectAll()
        self.connectButton = QPushButton("Connect")
        self.connectButton.setDefault(False)
        self.connectButton.setEnabled(True)
        layout = QVBoxLayout()
        layout.addWidget(self.browser)
        layout.addWidget(self.lineedit)
        layout.addWidget(self.connectButton)
        self.setLayout(layout)
        self.lineedit.setFocus()

        # Signals and slots for line edit and connect button
        self.lineedit.returnPressed.connect(self.sendToServer)
        self.connectButton.released.connect(self.connectToServer)

        self.setWindowTitle("Client")

        # Signals and slots for networking
        self.socket.readyRead.connect(self.readFromServer)
        self.socket.disconnected.connect(self.serverHasStopped)
        self.connect(self.socket,
                     SIGNAL("error(QAbstractSocket::SocketError)"),
                     self.serverHasError)

    # Update GUI
    def updateUi(self, text):
        self.browser.append(text)

    # Create connection to server
    def connectToServer(self):
        self.connectButton.setEnabled(False)
        print("Connecting to server")
        self.socket.connectToHost("localhost", PORT)

    # Send data to server
    def sendToServer(self):
        self.request = QByteArray()
        stream = QDataStream(self.request, QIODevice.WriteOnly)
        stream.setVersion(QDataStream.Qt_4_2)
        stream.writeUInt16(0)
        stream.writeQString(self.lineedit.text())
        stream.device().seek(0)
        stream.writeUInt16(self.request.size() - SIZEOF_UINT16)
        self.socket.write(self.request)
        self.nextBlockSize = 0
        self.request = None
        self.lineedit.setText("")

    # Read data from server and update Text Browser
    def readFromServer(self):
        stream = QDataStream(self.socket)
        stream.setVersion(QDataStream.Qt_4_2)

        while True:
            if self.nextBlockSize == 0:
                if self.socket.bytesAvailable() < SIZEOF_UINT16:
                    break
                self.nextBlockSize = stream.readUInt16()
            if self.socket.bytesAvailable() < self.nextBlockSize:
                break
            textFromServer = stream.readQString()
            self.updateUi(textFromServer)
            self.nextBlockSize = 0

    def serverHasStopped(self):
        self.socket.close()

    def serverHasError(self):
        self.updateUi("Error: {}".format(
                self.socket.errorString()))
        self.socket.close()


app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()

Answer 1

对你们大多数人来说可能是非常明显的,我并不完全明白如何处理线程!不用担心,我发现了一种设计服务器的方法,该服务器可以向多个客户端发送数据,而无需找到辅助线程.

很简单,真的,但在最好的时候我不是最快的猫.

服务器:

#!/usr/bin/env python3

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtNetwork import *

PORT = 9999
SIZEOF_UINT32 = 4

class ServerDlg(QPushButton):

    def __init__(self, parent=None):
        super(ServerDlg, self).__init__(
                "&Close Server", parent)
        self.setWindowFlags(Qt.WindowStaysOnTopHint)

        self.tcpServer = QTcpServer(self)               
        self.tcpServer.listen(QHostAddress("0.0.0.0"), PORT)
        self.connect(self.tcpServer, SIGNAL("newConnection()"), 
                    self.addConnection)
        self.connections = []

        self.connect(self, SIGNAL("clicked()"), self.close)
        font = self.font()
        font.setPointSize(24)
        self.setFont(font)
        self.setWindowTitle("Server")

    def addConnection(self):
        clientConnection = self.tcpServer.nextPendingConnection()
        clientConnection.nextBlockSize = 0
        self.connections.append(clientConnection)

        self.connect(clientConnection, SIGNAL("readyRead()"), 
                self.receiveMessage)
        self.connect(clientConnection, SIGNAL("disconnected()"), 
                self.removeConnection)
        self.connect(clientConnection, SIGNAL("error()"), 
                self.socketError)

    def receiveMessage(self):
        for s in self.connections:
            if s.bytesAvailable() > 0:
                stream = QDataStream(s)
                stream.setVersion(QDataStream.Qt_4_2)

                if s.nextBlockSize == 0:
                    if s.bytesAvailable() < SIZEOF_UINT32:
                        return
                    s.nextBlockSize = stream.readUInt32()
                if s.bytesAvailable() < s.nextBlockSize:
                    return

                textFromClient = stream.readQString()
                s.nextBlockSize = 0
                self.sendMessage(textFromClient, 
                                 s.socketDescriptor())
                s.nextBlockSize = 0

    def sendMessage(self, text, socketId):
        for s in self.connections:
            if s.socketDescriptor() == socketId:
                message = "You> {}".format(text)
            else:
                message = "{}> {}".format(socketId, text)
            reply = QByteArray()
            stream = QDataStream(reply, QIODevice.WriteOnly)
            stream.setVersion(QDataStream.Qt_4_2)
            stream.writeUInt32(0)
            stream.writeQString(message)
            stream.device().seek(0)
            stream.writeUInt32(reply.size() - SIZEOF_UINT32)
            s.write(reply)

    def removeConnection(self):
        pass

    def socketError(self):
        pass


app = QApplication(sys.argv)
form = ServerDlg()
form.show()
form.move(0, 0)
app.exec_()

客户

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtNetwork import *

PORTS = (9998, 9999)
PORT = 9999
SIZEOF_UINT32 = 4

class Form(QDialog):

    def __init__(self, parent=None):
        super(Form, self).__init__(parent)

        # Ititialize socket
        self.socket = QTcpSocket()

        # Initialize data IO variables
        self.nextBlockSize = 0
        self.request = None

        # Create widgets/layout
        self.browser = QTextBrowser()
        self.lineedit = QLineEdit("Enter text here, dummy")
        self.lineedit.selectAll()
        self.connectButton = QPushButton("Connect")
        self.connectButton.setEnabled(True)
        layout = QVBoxLayout()
        layout.addWidget(self.browser)
        layout.addWidget(self.lineedit)
        layout.addWidget(self.connectButton)
        self.setLayout(layout)
        self.lineedit.setFocus()

        # Signals and slots for line edit and connect button
        self.lineedit.returnPressed.connect(self.issueRequest)
        self.connectButton.clicked.connect(self.connectToServer)

        self.setWindowTitle("Client")
        # Signals and slots for networking
        self.socket.readyRead.connect(self.readFromServer)
        self.socket.disconnected.connect(self.serverHasStopped)
        self.connect(self.socket,
                     SIGNAL("error(QAbstractSocket::SocketError)"),
                     self.serverHasError)

    # Update GUI
    def updateUi(self, text):
        self.browser.append(text)

    # Create connection to server
    def connectToServer(self):
        self.connectButton.setEnabled(False)
        self.socket.connectToHost("localhost", PORT)

    def issueRequest(self):
        self.request = QByteArray()
        stream = QDataStream(self.request, QIODevice.WriteOnly)
        stream.setVersion(QDataStream.Qt_4_2)
        stream.writeUInt32(0)
        stream.writeQString(self.lineedit.text())
        stream.device().seek(0)
        stream.writeUInt32(self.request.size() - SIZEOF_UINT32)
        self.socket.write(self.request)
        self.nextBlockSize = 0
        self.request = None
        self.lineedit.setText("")

    def readFromServer(self):
        stream = QDataStream(self.socket)
        stream.setVersion(QDataStream.Qt_4_2)

        while True:
            if self.nextBlockSize == 0:
                if self.socket.bytesAvailable() < SIZEOF_UINT32:
                    break
                self.nextBlockSize = stream.readUInt32()
            if self.socket.bytesAvailable() < self.nextBlockSize:
                break
            textFromServer = stream.readQString()
            self.updateUi(textFromServer)
            self.nextBlockSize = 0

    def serverHasStopped(self):
        self.socket.close()
        self.connectButton.setEnabled(True)

    def serverHasError(self):
        self.updateUi("Error: {}".format(
                self.socket.errorString()))
        self.socket.close()
        self.connectButton.setEnabled(True)


app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()

总而言之,每个客户端连接都会打开一个套接字,并且套接字会附加到所有客户端套接字的列表中.然后,当其中一个客户端发送文本时,服务器在客户端套接字上循环,找到具有bytesAvailable的那个,读入它,然后将消息发送给其他客户端.

我很想知道其他人可能会想到这种方法.陷阱,问题等

谢谢!