我无法连接到mqtt中的代理，我想知道为什么？

Question

有三个文件：broker.py；sub.py；pub.py

broker.py：

import logging
import asyncio
from hbmqtt.broker import Broker

logger = logging.getLogger(__name__)

config = {
    'listeners': {
        'default':{
            'type': 'tcp',
            'bind': 'localhost:9999' 
        }
    },
    'sys_interval': 10,
    'topic-check':{
        'enabled': False
    }
}

broker = Broker(config)

@asyncio.coroutine
def startBroker():
yield from broker.start()

if __name__ == '__main__':
formatter = "[%(asctime)s] :: %(levelname)s :: %(name)s :: %(message)s"
logging.basicConfig(level=logging.INFO, format=formatter)
asyncio.get_event_loop().run_until_complete(startBroker())
asyncio.get_event_loop().run_forever()

sub.py：

import paho.mqtt.client as mqtt

client = mqtt.Client()
client.connect('localhost', 9999)

def on_connect(client, userdata, flags, rc):
    print("Connected to a broker!")
    client.subscribe("LINTANGtopic/test")

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

while True:
    client.on_connect = on_connect
    client.on_message = on_message
    client.loop_forever

pub.py：

import paho.mqtt.client as mqtt

client = mqtt.Client()
client.connect('localhost', 9999)

while True:
    client.publish("LINTANGtopic/test", input('Message: '))

所以我首先打开了三个终端： 在第一个终端中，我输入了“pybroker.py”，它运行良好； 在第二个终端中，我输入了“py sub.py”，它不工作，在第二个终端中没有显示任何内容，应该显示“连接到代理”，尽管它使第一个终端显示：

[2020-07-29 14:01:41,925] :: INFO :: hbmqtt.broker :: Listener 'default': 1 connections acquired        
[2020-07-29 14:01:41,926] :: INFO :: hbmqtt.broker :: Connection from ::1:50450 on listener 'default'   
[2020-07-29 14:01:41,937] :: INFO :: transitions.core :: Exited state new
[2020-07-29 14:01:41,937] :: INFO :: transitions.core :: Entered state connected

在第三个终端，我输入了“py pub.py”，它显示如下：

D:\MQTT>py pub.py
Message: 

我需要使订户连接到一个经纪人，我想知道为什么会发生这种情况

Answer 1

sub.py无法按您的方式工作

首先client.loop_forever是一个函数，因此需要使用()调用

其次，while True:循环是冗余的，您不应该重复设置回调

请尝试以下操作：

import paho.mqtt.client as mqtt

def on_connect(client, userdata, flags, rc):
    print("Connected to a broker!")
    client.subscribe("LINTANGtopic/test")

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

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.connect('localhost', 9999)
client.loop_forever()