不必使用线程，只需遵循Qt的逻辑：让我们使用信号。在下面的代码中，我展示了我正在实现的MQTT客户端库的高级功能，至少到现在为止已经实现了所需的功能，在接下来的几天中，我将添加更多的功能。
from PyQt5 import QtCore, QtWidgetsimport paho.mqtt.client as mqttclass MqttClient(QtCore.QObject): Disconnected = 0 Connecting = 1 Connected = 2 MQTT_3_1 = mqtt.MQTTv31 MQTT_3_1_1 = mqtt.MQTTv311 connected = QtCore.pyqtSignal() disconnected = QtCore.pyqtSignal() stateChanged = QtCore.pyqtSignal(int) hostnameChanged = QtCore.pyqtSignal(str) portChanged = QtCore.pyqtSignal(int) keepAliveChanged = QtCore.pyqtSignal(int) cleanSessionChanged = QtCore.pyqtSignal(bool) protocolVersionChanged = QtCore.pyqtSignal(int) messageSignal = QtCore.pyqtSignal(str) def __init__(self, parent=None): super(MqttClient, self).__init__(parent) self.m_hostname = "" self.m_port = 1883 self.m_keepAlive = 60 self.m_cleanSession = True self.m_protocolVersion = MqttClient.MQTT_3_1 self.m_state = MqttClient.Disconnected self.m_client = mqtt.Client(clean_session=self.m_cleanSession, protocol=self.protocolVersion) self.m_client.on_connect = self.on_connect self.m_client.on_message = self.on_message self.m_client.on_disconnect = self.on_disconnect @QtCore.pyqtProperty(int, notify=stateChanged) def state(self): return self.m_state @state.setter def state(self, state): if self.m_state == state: return self.m_state = state self.stateChanged.emit(state) @QtCore.pyqtProperty(str, notify=hostnameChanged) def hostname(self): return self.m_hostname @hostname.setter def hostname(self, hostname): if self.m_hostname == hostname: return self.m_hostname = hostname self.hostnameChanged.emit(hostname) @QtCore.pyqtProperty(int, notify=portChanged) def port(self): return self.m_port @port.setter def port(self, port): if self.m_port == port: return self.m_port = port self.portChanged.emit(port) @QtCore.pyqtProperty(int, notify=keepAliveChanged) def keepAlive(self): return self.m_keepAlive @keepAlive.setter def keepAlive(self, keepAlive): if self.m_keepAlive == keepAlive: return self.m_keepAlive = keepAlive self.keepAliveChanged.emit(keepAlive) @QtCore.pyqtProperty(bool, notify=cleanSessionChanged) def cleanSession(self): return self.m_cleanSession @cleanSession.setter def cleanSession(self, cleanSession): if self.m_cleanSession == cleanSession: return self.m_cleanSession = cleanSession self.cleanSessionChanged.emit(cleanSession) @QtCore.pyqtProperty(int, notify=protocolVersionChanged) def protocolVersion(self): return self.m_protocolVersion @protocolVersion.setter def protocolVersion(self, protocolVersion): if self.m_protocolVersion == protocolVersion: return if protocolVersion in (MqttClient.MQTT_3_1, MQTT_3_1_1): self.m_protocolVersion = protocolVersion self.protocolVersionChanged.emit(protocolVersion) ################################################################# @QtCore.pyqtSlot() def connectToHost(self): if self.m_hostname: self.m_client.connect(self.m_hostname, port=self.port, keepalive=self.keepAlive) self.state = MqttClient.Connecting self.m_client.loop_start() @QtCore.pyqtSlot() def disconnectFromHost(self): self.m_client.disconnect() def subscribe(self, path): if self.state == MqttClient.Connected: self.m_client.subscribe(path) ################################################################# # callbacks def on_message(self, mqttc, obj, msg): mstr = msg.payload.depre("ascii") # print("on_message", mstr, obj, mqttc) self.messageSignal.emit(mstr) def on_connect(self, *args): # print("on_connect", args) self.state = MqttClient.Connected self.connected.emit() def on_disconnect(self, *args): # print("on_disconnect", args) self.state = MqttClient.Disconnected self.disconnected.emit()class Widget(QtWidgets.QWidget): def __init__(self, parent=None): super(Widget, self).__init__(parent) lay = QtWidgets.QVBoxLayout(self) self.lcd_number = QtWidgets.QLCDNumber() lay.addWidget(self.lcd_number) self.client = MqttClient(self) self.client.stateChanged.connect(self.on_stateChanged) self.client.messageSignal.connect(self.on_messageSignal) self.client.hostname = "broker.hivemq.com" self.client.connectToHost() @QtCore.pyqtSlot(int) def on_stateChanged(self, state): if state == MqttClient.Connected: print(state) self.client.subscribe("shok2") @QtCore.pyqtSlot(str) def on_messageSignal(self, msg): try: val = float(msg) self.lcd_number.display(val) except ValueError: print("error: Not is number")if __name__ == '__main__': import sys app = QtWidgets.QApplication(sys.argv) w = Widget() w.show() sys.exit(app.exec_())- 基于此答案，我创建了一个库，将paho与PyQt5和PySide2结合使用：https
- //github.com/eyllanesc/qtmqtt
