我无法连接到 mqtt 中的代理，我想知道为什么？

Question

一共有三个文件：broker.py； 子.py; 酒吧.py;

经纪人.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()

子.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

发布.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，我输入了“py broker.py”，运行良好； 在第二个终端中，我输入了“py sub.py”，但它不起作用并且在第二个终端中没有显示任何内容，它应该显示“已连接到代理”，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

在第三个终端输入“py pub.py”，显示如下：

D:\MQTT>py pub.py
Message: 

我需要让订阅者连接到代理，我想知道为什么会这样？

Answer 1

sub.py 将无法正常工作。

首先client.loop_forever是一个 function 所以需要用()调用。

其次， while True:循环是多余的，您不应该重复设置回调。

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()