Paho MQTT回调未触发

Question

我正在使用Paho连接到我的MQTT brooker，但是，回调无法按预期方式工作。我已经按照文档进行操作，无法理解为什么函数会被忽略。

import paho.mqtt.client as mqtt
import mqttUtils as utils

# Subscribe To Topic


def subscribeToTopic(client, topic):
    try:
        result = client.subscribe(topic, 2)
        if result[0] == 0:
            utils.logging.info("Successfuly Subscribed To Topic")
            return 1
    except:
        utils.logging.info("Failed Subscribe Attempt")
        return 0


def on_subscribe(client, userdata, mid, granted_qos):  # subscribe to mqtt broker
    print("Subscribed", userdata)



host = "x"
client = mqtt.Client()
client.connect(host, port=1883, keepalive=60, bind_address="")
# result = utils.connectToMqtt(client,utils.host)
client.on_subscribe = on_subscribe
subscribeResult = subscribeToTopic(client, "test")

这是我的代码，我在订阅前声明了on_subscribe方法，但是脚本拒绝工作。有谁知道为什么不触发回调？

Answer 1

程序必须一直运行并从服务器接收消息，当从服务器获得确认后，它将运行on_subscribe。

您可以使用ie。

client.loop_forever() 

一直运行

import paho.mqtt.client as mqtt

def on_subscribe(client, userdata, mid, granted_qos):
    print("Subscribed", client, userdata, mid, granted_qos)

def on_message(client, userdata, message):
    #print('on_message:', client, userdata, message)
    #print(dir(message))
    print('on_message:', message.payload.decode())

host = "mqtt.eclipse.org"

client = mqtt.Client()
client.connect(host, port=1883, keepalive=60, bind_address="")
client.on_message = on_message
client.on_subscribe = on_subscribe
client.subscribe('temp', 1)

client.loop_forever()

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文档：paho-mqtt