在 paho-mqtt 中使用多个循环答案

【问题标题】：Using multiple loops in paho-mqtt在 paho-mqtt 中使用多个循环
【发布时间】：2023-01-21 18:35:43
【问题描述】：

我目前正在从事一个使用 Paho-MQTT 的项目。在我的代码中，我启动了一个 loop_forever 以读取来自某些主题的消息。

问题是我想将它们之间有一定延迟的消息发送到通道。通常 'time.sleep(4)' 可以增加延迟。出于某种原因，这似乎在我的代码中不起作用。

在这种情况下，还有其他方法可以在代码中添加延迟吗？

这是我目前拥有的 python 代码：

import time
import threading
import random
from flask import Flask, request
import paho.mqtt.client as mqtt
import socket

app = Flask(__name__)

# GLOBAL VARIABLES
game = "none"
button1 = "off"
button2 = "off"
button3 = "off"
button4 = "off"

score_team_blue = 0
score_team_red = 0

# turn on all led's mqqt


def on_all():
    for i in range(1, 5):
        client.publish(str(i), "0")
        time.sleep(1)
        client.publish(str(i), "off")



# MQQT CLIENT


def on_message(client, userdata, message):
    global game
    # print topic and message
    topic = message.topic
    message = message.payload.decode("utf-8")
    print(f"Topic: {topic}, Message: {message}")
    if topic == "games":
        if message == "memory":
            game = "memory"
            print("memory")
        elif message == "redblue":
            game = "redblue"
            print("redblue")
            redvsblue()
        elif message == "zen":
            game = "zen"
            print("zen")
        elif message == "minesweepr":
            game = "minesweepr"
            print("minesweepr")
    if topic == "buttons":
        if message == "1":
            # test_first_led()
            button1 = "on"
        elif message == "2":
            button2 = "on"
        elif message == "3":
            button3 = "on"
        elif message == "4":
            button4 = "on"

        # if game == "memory":
        #     # Do read button stuff voor memory
        #     print("memory button incoming")
        # elif game == "redblue":
        #     # Do read button stuff voor redblue
        #     print("red vs blue button incoming")
        # elif game == "zen":
        #     # Do read button stuff voor zen
        #     print("zen button incoming")
        # elif game == "minesweepr":
        #     # Do read button stuff voor minesweepr
        #     print("minesweeper button incoming")

def redvsblue():
    print('red vs blue')
    for i in range(1, 5):
        client.publish(str(i), "0")
        time.sleep(1)
        client.publish(str(i), "off")

client = mqtt.Client()
client.connect("127.0.0.1", 1883)
client.on_message = on_message
# MQTT CODE to send to the web server
# Subscribe to the topic "game"
client.subscribe("games")
client.subscribe("buttons")
client.loop_forever()

while True:
    print("Starting server")
    app.run(debug=False)

【问题讨论】：

标签： python mqtt paho

【解决方案1】：

loop_forever() 是一个阻塞调用，它永远不会返回。

您可以使用 loop_start()，它将在后台的单独线程上运行 MQTT 客户端网络查看。

请检查 Paho 文档以了解不同的循环选项：

https://www.eclipse.org/paho/index.php?page=clients/python/docs/index.php#network-loop

【讨论】：