Python QtNetwork.QTcpSocket.readAll() 和 QtNetwork.QTcpSocket.write() 不起作用

Posted 2023-02-16

【中文标题】Python QtNetwork.QTcpSocket.readAll() 和 QtNetwork.QTcpSocket.write() 不起作用

【英文标题】：Python QtNetwork.QTcpSocket.readAll() and QtNetwork.QTcpSocket.write() not working

【发布时间】：2018-11-20 11:45:15

【问题描述】：

我正在做一个简单的套接字连接，而 read.All() 和 write() 并没有给我任何回报。

import PySide.QtNetwork as Network
import PySide.QtCore as Core

proxyAddress = '127.0.0.1'
proxyPort = 1025
tcpSocket = Network.QTcpSocket()
tcpSocket.connectToHost(proxyAddress, proxyPort)

tcpSocket.state() 给出

"PySide.QtNetwork.QAbstractSocket.SocketState.ConnectingState"

当我尝试发送一些东西时，我得到了这个：

tcpSocket.write("Hello")
5L

对于 readAll()：

tcpSocket.readAll()
PySide.QtCore.QByteArray('')

哦，我尝试断开连接：

tcpSocket.disconnectFromHost()

它会返回下一行来写，就好像它成功断开连接但是当我检查状态时：

tcpSocket.state()
"PySide.QtNetwork.QAbstractSocket.SocketState.ConnectingState"

感谢任何帮助。

【参考方案1】：

首先，信号状态为ConnectingState，表示尚未建立连接，因此此时执行任何任务都不正确，您必须等待状态为ConnectedState。另一方面，您指出的端口可能正在被另一个应用程序使用，因为它通常是为另一个任务保留的一个小数字。在下一部分中，我将展示一个服务器和客户端的示例（首先启动服务器，然后您可以启动所需数量的客户端。）。最后，在 Qt 中，任务不应该同步执行，而是通过信号执行，因为 Qt 事件循环需要更新内部和外部变量状态。

server.py

import uuid
from PySide import QtCore, QtNetwork

class ServerManager(QtCore.QObject):
    def __init__(self, parent=None):
        super(ServerManager, self).__init__(parent)
        self._server = QtNetwork.QTcpServer(self)
        self._server.newConnection.connect(self.on_newConnection)
        self._clients = 

    def launch(self, address=QtNetwork.QHostAddress.Any, port=9999):
        return self._server.listen(QtNetwork.QHostAddress(address), port)

    @QtCore.Slot()
    def on_newConnection(self):
        socket = self._server.nextPendingConnection()
        socket.readyRead.connect(self.on_readyRead)
        if socket not in self._clients:
            self._clients[socket] = uuid.uuid4()

    @QtCore.Slot()
    def on_readyRead(self):
        socket = self.sender()
        resp = socket.readAll()
        code = self._clients[socket]
        print("From[]- message: ".format(code, resp))
        socket.write("Server: " + str(resp)[::-1])

if __name__ == '__main__':
    import sys
    import signal
    signal.signal(signal.SIGINT, signal.SIG_DFL)
    app = QtCore.QCoreApplication(sys.argv)

    address = '127.0.0.1'
    port = 9000
    server = ServerManager()
    if not server.launch(address, port):
        sys.exit(-1)
    sys.exit(app.exec_())

client.py

from PySide import QtCore, QtNetwork

class ClientManager(QtCore.QObject):
    def __init__(self, parent=None):
        super(ClientManager, self).__init__(parent)
        self._socket = QtNetwork.QTcpSocket(self)
        self._socket.stateChanged.connect(self.on_stateChanged)
        self._socket.readyRead.connect(self.on_readyRead)
        self._timer = QtCore.QTimer(self, interval=1000)
        self._timer.timeout.connect(self.sendMessage)

    def launch(self, address=QtNetwork.QHostAddress.Any, port=9999):
        return self._socket.connectToHost(QtNetwork.QHostAddress(address), port)

    @QtCore.Slot(QtNetwork.QAbstractSocket.SocketState)
    def on_stateChanged(self, state):
        if state == QtNetwork.QAbstractSocket.ConnectedState:
            self._timer.start()
            print("connected")
        elif state == QtNetwork.QAbstractSocket.UnconnectedState:
            print("disconnected")
            QtCore.QCoreApplication.quit()

    @QtCore.Slot()
    def sendMessage(self):
        if self._socket.state() == QtNetwork.QAbstractSocket.ConnectedState:
            msg = QtCore.QDateTime.currentDateTime().toString()
            self._socket.write(msg) 

    @QtCore.Slot()
    def on_readyRead(self):
        print("Response: ", self._socket.readAll())

if __name__ == '__main__':
    import sys
    import signal
    signal.signal(signal.SIGINT, signal.SIG_DFL)
    app = QtCore.QCoreApplication(sys.argv)
    address = '127.0.0.1'
    port = 9000
    server = ClientManager()
    server.launch(address, port)
    sys.exit(app.exec_())

【讨论】：

感谢您的评论。运行 connectToHost() 后我应该等待多长时间才能最终连接？它处于 ConnectingState 有一段时间了。

@mikanim 这取决于许多变量，例如网络、硬件等，因此没有答案。正确的做法是使用我在示例中显示的信号。