"# MQTT \u81ea\u52a8\u91cd\u8fde\u6700\u4f73\u5b9e\u8df5\n\n> 2023-07-10 | 2026-07-01\n> https:\/\/www.modbus.cn\/en\/20752.html\n\n**\u672a\u5206\u7c7b**\n\n---\n\n\u7406\u89e3\u548c\u5e94\u7528 MQTT \u534f\u8bae\u662f\u7269\u8054\u7f51\u9886\u57df\u4e2d\u7684\u4e00\u9879\u91cd\u8981\u6280\u80fd\u3002\u4e3a\u4e86\u786e\u4fdd\u8bbe\u5907\u548c\u670d\u52a1\u5668\u4e4b\u95f4\u7684\u7a33\u5b9a\u8fde\u63a5\uff0c\u6211\u4eec\u9700\u8981\u6df1\u5165\u4e86\u89e3\u5e76\u6709\u6548\u5e94\u7528 MQTT \u5ba2\u6237\u7aef\u7684\u81ea\u52a8\u91cd\u8fde\u7279\u6027\u3002\u4e0b\u9762\uff0c\u8ba9\u6211\u4eec\u50cf\u5728\u63a2\u7d22\u4e00\u4e2a\u795e\u79d8\u7684\u5192\u9669\u5c9b\u4e00\u6837\uff0c\u6df1\u5165\u63a2\u7d22 MQTT \u534f\u8bae\u548c\u91cd\u8fde\u673a\u5236\u3002\r\n\r\nMQTT \u662f\u4e00\u79cd\u57fa\u4e8e TCP \u534f\u8bae\u7684\u53d1\u5e03\/\u8ba2\u9605\u6a21\u578b\u534f\u8bae\u3002\u5b83\u50cf\u4e00\u8258\u7ecf\u8fc7\u98ce\u96e8\u6d17\u793c\u7684\u6d77\u8239\uff0c\u5728\u7269\u8054\u7f51\u3001\u4f20\u611f\u5668\u7f51\u7edc\u548c\u5176\u4ed6\u4f4e\u5e26\u5bbd\u3001\u4e0d\u7a33\u5b9a\u7f51\u7edc\u73af\u5883\u4e2d\u822a\u884c\u3002\u4f46\u662f\uff0c\u5c31\u50cf\u6d77\u4e0a\u7684\u98ce\u6d6a\uff0c\u7f51\u7edc\u73af\u5883\u4e2d\u4e5f\u5145\u6ee1\u4e86\u5404\u79cd\u6311\u6218\uff1a\u7f51\u7edc\u6545\u969c\u3001\u4fe1\u53f7\u5f31\u5316\u3001\u6570\u636e\u4e22\u5305\u7b49\u7b49\uff0c\u8fd9\u4e9b\u90fd\u53ef\u80fd\u4f7f\u5f97 MQTT \u5ba2\u6237\u7aef\u4e0e\u670d\u52a1\u5668\u4e4b\u95f4\u7684\u8fde\u63a5\u4e2d\u65ad\u3002\u5728\u7269\u8054\u7f51\u7684\u5927\u6d77\u4e2d\uff0c\u5e38\u89c1\u7684\u89e6\u53d1\u65ad\u7ebf\u91cd\u8fde\u7684\u98ce\u6d6a\u5305\u62ec\u7f51\u7edc\u73af\u5883\u6076\u52a3\u6216\u65ad\u7f51\u3001\u670d\u52a1\u5668\u5347\u7ea7\u3001\u8bbe\u5907\u6216\u5ba2\u6237\u7aef\u91cd\u542f\u3001\u4ee5\u53ca\u5176\u4ed6\u7f51\u7edc\u56e0\u7d20\u7b49\u3002\r\n\r\n\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u5982\u4f55\u786e\u4fdd\u6211\u4eec\u7684 \"\u8239\"\uff08MQTT \u5ba2\u6237\u7aef\uff09\u59cb\u7ec8\u80fd\u4e0e \"\u6e2f\u53e3\"\uff08\u670d\u52a1\u5668\uff09\u4fdd\u6301\u7a33\u5b9a\u7684\u8fde\u63a5\u5462\uff1f\u7b54\u6848\u5c31\u662f\u6211\u4eec\u9700\u8981\u7ed9\u6211\u4eec\u7684 \"\u8239\" \u88c5\u5907\u4e00\u5957\u81ea\u52a8\u5bfc\u822a\u7cfb\u7edf\u2014\u2014MQTT \u5ba2\u6237\u7aef\u7684\u81ea\u52a8\u91cd\u8fde\u903b\u8f91\u3002\r\n\r\n\u8bbe\u8ba1\u4e00\u4e2a\u4f18\u79c0\u7684 MQTT \u5ba2\u6237\u7aef\u91cd\u8fde\u903b\u8f91\uff0c\u5c31\u50cf\u5efa\u9020\u4e00\u8258\u575a\u56fa\u7684\u6d77\u8239\u3002\u5982\u679c\u8bbe\u8ba1\u5f97\u4e0d\u5408\u7406\uff0c\u90a3\u4e48\u6211\u4eec\u7684 \"\u8239\" \u53ef\u80fd\u4f1a\u5931\u53bb\u5bfc\u822a\uff0c\u9759\u9ed8\u4e0d\u518d\u63a5\u6536\u6765\u81ea \"\u6e2f\u53e3\" \u7684\u6d88\u606f\uff0c\u751a\u81f3\u53ef\u80fd\u4f1a\u56e0\u4e3a\u9891\u7e41\u5730\u5c1d\u8bd5\u91cd\u8fde\u800c\u65e0\u610f\u8bc6\u5730\u653b\u51fb\u6211\u4eec\u7684 \"\u6e2f\u53e3\"\uff0c\u8fd9\u5c31\u5982\u540c\u5728\u6d77\u4e0a\u65e0\u5934\u4e71\u7a9c\uff0c\u4e0d\u4ec5\u6d88\u8017\u4e86\u81ea\u8eab\u7684\u80fd\u91cf\uff0c\u4e5f\u7ed9 \"\u6e2f\u53e3\" \u5e26\u6765\u4e86\u4e0d\u5fc5\u8981\u7684\u538b\u529b\u3002\u7136\u800c\uff0c\u5982\u679c\u6211\u4eec\u7684\u91cd\u8fde\u903b\u8f91\u8bbe\u8ba1\u5f97\u5408\u7406\uff0c\u90a3\u4e48\u65e0\u8bba\u4f55\u65f6\u5931\u53bb\u8fde\u63a5\uff0c\u6211\u4eec\u7684 \"\u8239\" \u90fd\u80fd\u7a33\u5b9a\u5730\u81ea\u52a8\u5bfc\u822a\uff0c\u91cd\u65b0\u627e\u5230 \"\u6e2f\u53e3\"\uff0c\u5e76\u4fdd\u6301\u4e0e\u5176\u7684\u8fde\u63a5\u3002\r\n\r\n\u8bbe\u8ba1 MQTT \u5ba2\u6237\u7aef\u91cd\u8fde\u903b\u8f91\u65f6\uff0c\u6211\u4eec\u9700\u8981\u8003\u8651\u51e0\u4e2a\u5173\u952e\u56e0\u7d20\uff1a\r\n\r\n \t- **\u822a\u884c\u4fdd\u6d3b\u65f6\u95f4**\uff1a\u5728 MQTT \u4e2d\uff0c\u6211\u4eec\u79f0\u5176\u4e3a Keep Alive\u3002\u8fd9\u662f\u4e00\u4e2a\u5b9a\u65f6\u5668\uff0c\u5b83\u4f1a\u5b9a\u671f\u68c0\u67e5\u6211\u4eec\u7684 \"\u8239\" \u662f\u5426\u4e0e \"\u6e2f\u53e3\" \u4fdd\u6301\u8fde\u63a5\u3002\u6211\u4eec\u9700\u8981\u6839\u636e\u5b9e\u9645\u7684\u7f51\u7edc\u73af\u5883\u548c\u5e94\u7528\u9700\u6c42\uff0c\u6765\u8bbe\u7f6e\u4e00\u4e2a\u5408\u9002\u7684 Keep Alive\u3002\r\n \t- **\u91cd\u8fde\u7b56\u7565\u548c\u9000\u907f**\uff1a\u5f53\u6211\u4eec\u7684 \"\u8239\" \u5931\u53bb\u4e86\u4e0e \"\u6e2f\u53e3\" \u7684\u8fde\u63a5\uff0c\u6211\u4eec\u4e0d\u5e94\u7acb\u523b\u5c1d\u8bd5\u91cd\u65b0\u8fde\u63a5\uff0c\u800c\u5e94\u8be5\u8bbe\u7f6e\u4e00\u4e2a\u5408\u7406\u7684\u7b49\u5f85\u65f6\u95f4\uff0c\u4ee5\u514d\u8fc7\u5ea6\u6d88\u8017\u8d44\u6e90\u3002\u8fd9\u5c31\u50cf\u662f\u5f53\u6211\u4eec\u7684\u8239\u5728\u6d77\u4e0a\u8ff7\u8def\u65f6\uff0c\u6211\u4eec\u9700\u8981\u6682\u65f6\u505c\u4e0b\uff0c\u89c2\u5bdf\u98ce\u5411\u3001\u6d4b\u91cf\u6d77\u6d41\uff0c\u7136\u540e\u518d\u5236\u5b9a\u65b0\u7684\u822a\u884c\u8def\u7ebf\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u6307\u6570\u9000\u907f\u7b97\u6cd5\u6216\u8005\u9636\u68af\u5f0f\u7684\u5ef6\u65f6\u7b56\u7565\u6765\u5b9e\u73b0\u8fd9\u4e2a\u529f\u80fd\u3002\r\n \t- **\u8fde\u63a5\u72b6\u6001\u7ba1\u7406**\uff1a\u6211\u4eec\u7684 \"\u8239\" \u9700\u8981\u4e00\u4e2a\u822a\u6d77\u65e5\u5fd7\uff0c\u6765\u8bb0\u5f55\u4e0e \"\u6e2f\u53e3\" \u7684\u8fde\u63a5\u72b6\u6001\u3001\u8fde\u63a5\u65ad\u5f00\u7684\u539f\u56e0\u3001\u5df2\u7ecf\u8ba2\u9605\u7684\u4fe1\u606f\u7b49\u91cd\u8981\u4fe1\u606f\u3002\u5728\u8fde\u63a5\u65ad\u5f00\u65f6\uff0c\u6211\u4eec\u7684 \"\u8239\" \u5e94\u8be5\u67e5\u9605\u822a\u6d77\u65e5\u5fd7\uff0c\u5206\u6790\u8fde\u63a5\u65ad\u5f00\u7684\u539f\u56e0\uff0c\u7136\u540e\u5c1d\u8bd5\u91cd\u65b0\u8fde\u63a5 \"\u6e2f\u53e3\"\u3002\r\n \t- **\u5f02\u5e38\u5904\u7406**\uff1a\u5728\u822a\u884c\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7684 \"\u8239\" \u53ef\u80fd\u4f1a\u9047\u5230\u5404\u79cd\u5404\u6837\u7684\u95ee\u9898\uff0c\u4f8b\u5982 \"\u6e2f\u53e3\" \u4e0d\u53ef\u7528\u3001\u8ba4\u8bc1\u5931\u8d25\u3001\u7f51\u7edc\u5f02\u5e38\u7b49\u3002\u6211\u4eec\u7684 \"\u8239\" \u9700\u8981\u6709\u4e00\u4e2a\u5e94\u6025\u8ba1\u5212\uff0c\u6765\u5e94\u5bf9\u8fd9\u4e9b\u95ee\u9898\u3002\u4f8b\u5982\uff0c\u5f53 \"\u6e2f\u53e3\" \u4e0d\u53ef\u7528\u65f6\uff0c\u6211\u4eec\u7684 \"\u8239\" \u53ef\u80fd\u9700\u8981\u5bfb\u627e\u5176\u4ed6\u7684 \"\u6e2f\u53e3\"\uff1b\u5f53\u8ba4\u8bc1\u5931\u8d25\u65f6\uff0c\u6211\u4eec\u7684 \"\u8239\" \u53ef\u80fd\u9700\u8981\u68c0\u67e5\u81ea\u8eab\u7684\u8ba4\u8bc1\u4fe1\u606f\u662f\u5426\u6b63\u786e\uff1b\u5f53\u7f51\u7edc\u5f02\u5e38\u65f6\uff0c\u6211\u4eec\u7684 \"\u8239\" \u53ef\u80fd\u9700\u8981\u6682\u505c\u822a\u884c\uff0c\u7b49\u5f85\u7f51\u7edc\u6062\u590d\u6b63\u5e38\u3002\r\n \t- **\u6700\u5927\u5c1d\u8bd5\u6b21\u6570\u9650\u5236**\uff1a\u5bf9\u4e8e\u4e00\u4e9b\u4f4e\u529f\u8017\u8bbe\u5907\uff0c\u6211\u4eec\u53ef\u80fd\u9700\u8981\u8003\u8651\u9650\u5236\u5c1d\u8bd5\u91cd\u8fde\u7684\u6b21\u6570\uff0c\u4ee5\u907f\u514d\u8fc7\u5ea6\u6d88\u8017\u8bbe\u5907\u7684\u7535\u529b\u3002\u5c31\u50cf\u5728\u6d77\u4e0a\u8ff7\u822a\u7684 \"\u8239\"\uff0c\u5f53\u5b83\u5df2\u7ecf\u5c1d\u8bd5\u4e86\u5f88\u591a\u6b21\u90fd\u65e0\u6cd5\u627e\u5230 \"\u6e2f\u53e3\" \u65f6\uff0c\u53ef\u80fd\u5c31\u9700\u8981\u6682\u65f6\u505c\u4e0b\uff0c\u7b49\u5f85\u66f4\u597d\u7684\u822a\u884c\u6761\u4ef6\u3002\r\n\r\n\u5728\u8bbe\u8ba1\u4e86\u8fd9\u4e2a\u81ea\u52a8\u5bfc\u822a\u7cfb\u7edf\uff08MQTT \u5ba2\u6237\u7aef\u7684\u81ea\u52a8\u91cd\u8fde\u903b\u8f91\uff09\u4e4b\u540e\uff0c\u6211\u4eec\u7684 \"\u8239\" \u5c31\u80fd\u66f4\u597d\u5730\u5728\u7269\u8054\u7f51\u7684\u6d77\u6d0b\u4e2d\u822a\u884c\uff0c\u65e0\u8bba\u9762\u4e34\u4f55\u79cd\u6311\u6218\uff0c\u90fd\u80fd\u59cb\u7ec8\u4fdd\u6301\u4e0e \"\u6e2f\u53e3\" \u7684\u7a33\u5b9a\u8fde\u63a5\uff0c\u4ece\u800c\u786e\u4fdd\u6211\u4eec\u7684\u5e94\u7528\u80fd\u591f\u987a\u5229\u8fdb\u884c\u3002\r\n\r\n\u6765\u770b\u4e00\u4e2a\u5b9e\u9645\u7684\u6848\u4f8b\u3002\u6211\u4eec\u4ee5 Paho MQTT C \u5e93\u4e3a\u4f8b\uff0c\u5b83\u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86\u4e00\u5957\u4e30\u5bcc\u7684\u822a\u6d77\u5de5\u5177\u2014\u2014\u56de\u8c03\u51fd\u6570\uff0c\u8ba9\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u5b9e\u9645\u60c5\u51b5\u8bbe\u5b9a\u81ea\u52a8\u5bfc\u822a\u7cfb\u7edf\u7684\u5de5\u4f5c\u65b9\u5f0f\u3002Paho \u63d0\u4f9b\u4e86\u5168\u5c40\u56de\u8c03\u3001API \u56de\u8c03\u548c\u5f02\u6b65\u65b9\u6cd5\u56de\u8c03\uff0c\u8ba9\u6211\u4eec\u53ef\u4ee5\u5728\u5404\u79cd\u60c5\u51b5\u4e0b\u90fd\u80fd\u4fdd\u6301\u4e0e \"\u6e2f\u53e3\" \u7684\u8fde\u63a5\u3002\r\n\r\n\u8fd9\u5c31\u662f\u6211\u4eec\u5982\u4f55\u5728\u7269\u8054\u7f51\u7684\u6d77\u6d0b\u4e2d\u822a\u884c\u7684\u6545\u4e8b\u3002\u5e0c\u671b\u901a\u8fc7\u8fd9\u4e2a\u6545\u4e8b\uff0c\u80fd\u591f\u5e2e\u52a9\u4f60\u66f4\u597d\u5730\u7406\u89e3 MQTT \u534f\u8bae\u548c\u91cd\u8fde\u673a\u5236\uff0c\u4e5f\u5e0c\u671b\u4f60\u7684 \"\u8239\" \u80fd\u5728\u7269\u8054\u7f51\u7684\u6d77\u6d0b\u4e2d\u987a\u5229\u822a\u884c\u3002\r\n\r\n \r\n\r\n\n```\n\/*******************************************************************************\r\n * Copyright (c) 2012, 2022 IBM Corp., Ian Craggs\r\n *\r\n * \u4fdd\u7559\u6240\u6709\u6743\u5229\u3002\u6b64\u7a0b\u5e8f\u548c\u968f\u9644\u7684\u8d44\u6599\r\n * \u6839\u636eEclipse\u516c\u5171\u8bb8\u53ef\u8bc1v2.0\r\n * \u548cEclipse\u53d1\u884c\u8bb8\u53ef\u8bc1v1.0\u7684\u6761\u6b3e\u63d0\u4f9b\u3002 \r\n *\r\n * Eclipse\u516c\u5171\u8bb8\u53ef\u8bc1\u53ef\u5728\u4ee5\u4e0b\u7f51\u5740\u67e5\u9605 \r\n *   https:\/\/www.eclipse.org\/legal\/epl-2.0\/\r\n * Eclipse\u53d1\u884c\u8bb8\u53ef\u8bc1\u53ef\u5728\u4ee5\u4e0b\u7f51\u5740\u67e5\u9605 \r\n *   http:\/\/www.eclipse.org\/org\/documents\/edl-v10.php\u3002\r\n *\r\n *******************************************************************************\/\r\n\r\n#include <stdio.h>\r\n#include <stdlib.h>\r\n#include <string.h>\r\n#include \"MQTTAsync.h\"\r\n\r\n#if !defined(_WIN32)\r\n#include <unistd.h>\r\n#else\r\n#include <windows.h>\r\n#endif\r\n\r\n#if defined(_WRS_KERNEL)\r\n#include <OsWrapper.h>\r\n#endif\r\n\r\n\/\/ \u5b9a\u4e49\u9700\u8981\u4f7f\u7528\u7684MQTT\u8fde\u63a5\u53c2\u6570\uff0c\u5982broker\u5730\u5740\u548c\u5ba2\u6237\u7aefID\u7b49\r\n#define ADDRESS     \"tcp:\/\/broker.emqx.io:1883\"\r\n#define CLIENTID    \"PahoClientSub\"\r\n#define TOPIC       \"nanomq\/test\"\r\n#define PAYLOAD     \"Hello World!\"\r\n#define QOS         1\r\n#define TIMEOUT     10000L\r\n\r\n\/\/ \u5b9a\u4e49\u5728\u4e3b\u7ebf\u7a0b\u4e2d\u7684\u903b\u8f91Flag\r\nint disc_finished = 0;\r\nint subscribed = 0;\r\nint finished = 0;\r\n\r\n\/\/\u9996\u5148\u58f0\u660e API \u56de\u8c03\u51fd\u6570\r\nvoid onConnect(void* context, MQTTAsync_successData* response);\r\nvoid onConnectFailure(void* context, MQTTAsync_failureData* response);\r\nvoid onSubscribe(void* context, MQTTAsync_successData* response);\r\nvoid onSubscribeFailure(void* context, MQTTAsync_failureData* response);\r\n\r\n\/\/ \u4e0b\u97622\u4e2a\u662f Async \u4f7f\u7528\u7684\u56de\u8c03\u51fd\u6570\r\n\/\/ \u5f02\u6b65\u8fde\u63a5\u6210\u529f\u7684\u56de\u8c03\u51fd\u6570\uff0c\u5728\u8fde\u63a5\u6210\u529f\u7684\u65f6\u5019\u8fdb\u884cSubscribe\u64cd\u4f5c\u3002\r\nvoid conn_established(void *context, char *cause)\r\n{\r\n\tprintf(\"\u5ba2\u6237\u7aef\u5df2\u91cd\u65b0\u8fde\u63a5!\\n\");\r\n\tMQTTAsync client = (MQTTAsync)context;\r\n\tMQTTAsync_responseOptions opts = MQTTAsync_responseOptions_initializer;\r\n\tint rc;\r\n\r\n\tprintf(\"\u8fde\u63a5\u6210\u529f\\n\");\r\n\r\n\tprintf(\"\u8ba2\u9605\u4e3b\u9898 %s\\n\u4f7f\u7528\u5ba2\u6237\u7aef %s \u5e76\u7528QoS%d\\n\\n\"\r\n           \"\u6309Q<Enter>\u9000\u51fa\\n\\n\", TOPIC, CLIENTID, QOS);\r\n\topts.onSuccess = onSubscribe;\r\n\topts.onFailure = onSubscribeFailure;\r\n\topts.context = client;\r\n\tif ((rc = MQTTAsync_subscribe(client, TOPIC, QOS, &opts)) != MQTTASYNC_SUCCESS)\r\n\t{\r\n\t\tprintf(\"\u5f00\u59cb\u8ba2\u9605\u5931\u8d25\uff0c\u8fd4\u56de\u7801 %d\\n\", rc);\r\n\t\tfinished = 1;\r\n\t}\r\n}\r\n\r\n\/\/ \u5f02\u6b65\u8fde\u63a5\u6536\u5230 Disconnect\u6d88\u606f\u65f6\u7684\u56de\u8c03\uff0c\u7531\u4e8e\u5927\u90e8\u5206\u65ad\u5f00\u7684\u60c5\u51b5\u4e0b\u4e0d\u4f1a\u6536\u5230 Disconnect\u6d88\u606f\uff0c\u6240\u4ee5\u6b64\u65b9\u6cd5\u5f88\u5c11\u88ab\u89e6\u53d1\r\nvoid disconnect_lost(void* context, MQTTProperties* properties,\r\n\t\tenum MQTTReasonCodes reasonCode)\r\n{\r\n\tprintf(\"\u5ba2\u6237\u7aef\u5df2\u65ad\u5f00\u8fde\u63a5!\\n\");\r\n}\r\n\r\n\/\/ \u4e0b\u9762\u662f\u5ba2\u6237\u7aef\u5168\u5c40\u56de\u8c03\u51fd\u6570\uff0c\u5206\u522b\u662f\u8fde\u63a5\u65ad\u5f00\u548c\u6d88\u606f\u5230\u8fbe\r\nvoid conn_lost(void *context, char *cause)\r\n{\r\n\tMQTTAsync client = (MQTTAsync)context;\r\n\tMQTTAsync_connectOptions conn_opts = MQTTAsync_connectOptions_initializer;\r\n\tint rc;\r\n\r\n\tprintf(\"\\n\u8fde\u63a5\u5df2\u65ad\u5f00\\n\");\r\n\tif (cause)\r\n\t\tprintf(\"     \u539f\u56e0: %s\\n\", cause);\r\n\r\n\tprintf(\"\u6b63\u5728\u91cd\u8fde\\n\");\r\n\tconn_opts.keepAliveInterval = 20;\r\n\tconn_opts.cleansession = 1;\r\n\tconn_opts.maxRetryInterval = 16;\r\n\tconn_opts.minRetryInterval = 2;\r\n\tconn_opts.automaticReconnect = 1;\r\n\t\r\n\t\/\/conn_opts.onSuccess = onConnect;\r\n\tconn_opts.onFailure = onConnectFailure;\r\n\tMQTTAsync_setConnected(client, client, conn_established);\r\n\tif ((rc = MQTTAsync_connect(client, &conn_opts)) != MQTTASYNC_SUCCESS)\r\n\t{\r\n\t\tprintf(\"\u5f00\u59cb\u8fde\u63a5\u5931\u8d25\uff0c\u8fd4\u56de\u7801 %d\\n\", rc);\r\n\t\tfinished = 1;\r\n\t}\r\n}\r\n\r\n\/\/ \u6536\u5230\u6d88\u606f\u65f6\u7684\u5168\u5c40\u56de\u8c03\u51fd\u6570\uff0c\u6b64\u5904\u7b80\u5355\u7684\u6253\u5370\u6d88\u606f\r\nint msgarrvd(void *context, char *topicName, int topicLen, MQTTAsync_message *message)\r\n{\r\n    printf(\"\u6d88\u606f\u5df2\u5230\u8fbe\\n\");\r\n    printf(\"     \u4e3b\u9898: %s\\n\", topicName);\r\n    printf(\"   \u6d88```C\r\n\u606f: \");\r\n\r\n    \/* \u6253\u5370\u6d88\u606f\u5185\u5bb9 *\/\r\n    char* payloadptr = message->payload;\r\n    for(int i = 0; i < message->payloadlen; i++)\r\n    {\r\n        putchar(*payloadptr++);\r\n    }\r\n    putchar('\\n');\r\n\r\n    \/* \u91ca\u653e\u6d88\u606f\u5185\u5b58 *\/\r\n    MQTTAsync_freeMessage(&message);\r\n    MQTTAsync_free(topicName);\r\n\r\n    return 1;\r\n}\r\n\r\n\/* \u5f02\u6b65\u65ad\u5f00\u8fde\u63a5\u7684\u56de\u8c03\u51fd\u6570 *\/\r\nvoid onDisconnect(void* context, MQTTAsync_successData* response)\r\n{\r\n    printf(\"\u6210\u529f\u65ad\u5f00\u8fde\u63a5\\n\");\r\n    disc_finished = 1;\r\n}\r\n\r\n\/* \u5f02\u6b65\u8fde\u63a5\u6210\u529f\u7684\u56de\u8c03\u51fd\u6570\uff0c\u5728\u8fde\u63a5\u6210\u529f\u7684\u65f6\u5019\u8fdb\u884c\u8ba2\u9605\u64cd\u4f5c\u3002 *\/\r\nvoid onConnect(void* context, MQTTAsync_successData* response)\r\n{\r\n    MQTTAsync client = (MQTTAsync)context;\r\n    MQTTAsync_responseOptions opts = MQTTAsync_responseOptions_initializer;\r\n    int rc;\r\n\r\n    printf(\"\u6210\u529f\u8fde\u63a5\\n\");\r\n\r\n    printf(\"\u8ba2\u9605\u4e3b\u9898 %s\\n\u4f7f\u7528\u5ba2\u6237\u7aef %s \u5e76\u7528QoS%d\\n\\n\"\r\n           \"\u6309Q<Enter>\u9000\u51fa\\n\\n\", TOPIC, CLIENTID, QOS);\r\n\r\n    \/* \u5f00\u59cb\u8ba2\u9605 *\/\r\n    opts.onSuccess = onSubscribe;\r\n    opts.onFailure = onSubscribeFailure;\r\n    opts.context = client;\r\n    if ((rc = MQTTAsync_subscribe(client, TOPIC, QOS, &opts)) != MQTTASYNC_SUCCESS)\r\n    {\r\n        printf(\"\u5f00\u59cb\u8ba2\u9605\u5931\u8d25\uff0c\u8fd4\u56de\u7801 %d\\n\", rc);\r\n        finished = 1;\r\n    }\r\n}\r\n\r\n\/* \u5f02\u6b65\u8fde\u63a5\u5931\u8d25\u7684\u56de\u8c03\u51fd\u6570 *\/\r\nvoid onConnectFailure(void* context, MQTTAsync_failureData* response)\r\n{\r\n    printf(\"\u8fde\u63a5\u5931\u8d25\\n\");\r\n    if (response && response->message)\r\n    {\r\n        printf(\"\u5931\u8d25\u4fe1\u606f: %s\\n\", response->message);\r\n    }\r\n    finished = 1;\r\n}\r\n\r\n\/* \u5f02\u6b65\u8ba2\u9605\u6210\u529f\u7684\u56de\u8c03\u51fd\u6570 *\/\r\nvoid onSubscribe(void* context, MQTTAsync_successData* response)\r\n{\r\n    printf(\"\u6210\u529f\u8ba2\u9605\\n\");\r\n    subscribed = 1;\r\n}\r\n\r\n\/* \u5f02\u6b65\u8ba2\u9605\u5931\u8d25\u7684\u56de\u8c03\u51fd\u6570 *\/\r\nvoid onSubscribeFailure(void* context, MQTTAsync_failureData* response)\r\n{\r\n    printf(\"\u8ba2\u9605\u5931\u8d25\\n\");\r\n    if (response && response->message)\r\n    {\r\n        printf(\"\u5931\u8d25\u4fe1\u606f: %s\\n\", response->message);\r\n    }\r\n    finished = 1;\r\n}\r\n\r\n\/* \u5f02\u6b65\u53d6\u6d88\u8ba2\u9605\u7684\u56de\u8c03\u51fd\u6570 *\/\r\nvoid onUnsubscribe(void* context, MQTTAsync_successData* response)\r\n{\r\n    printf(\"\u6210\u529f\u53d6\u6d88\u8ba2\u9605\\n\");\r\n    finished = 1;\r\n}\r\n\r\nint main(int argc, char* argv[])\r\n{\r\n    MQTTAsync client;\r\n    MQTTAsync_connectOptions conn_opts = MQTTAsync_connectOptions_initializer;\r\n    int rc;\r\n    MQTTAsync_message pubmsg = MQTTAsync_message_initializer;\r\n    MQTTAsync_token token;\r\n\r\n    \/* \u521b\u5efaMQTT\u5ba2\u6237\u7aef *\/\r\n    MQTTAsync_create(&client, ADDRESS, CLIENTID, MQTTCLIENT_PERSISTENCE_NONE, NULL);\r\n\r\n    \/* \u8bbe\u7f6e\u5168\u5c40\u56de\u8c03\u51fd\u6570 *\/\r\n    MQTTAsync_setCallbacks(client, client, conn_lost, msgarrvd, NULL);\r\n\r\n    \/* \u8bbe\u7f6e\u8fde\u63a5\u9009\u9879 *\/\r\n    conn_opts.keepAliveInterval = 20;\r\n    conn_opts.cleansession = 1;\r\n    conn_opts.automaticReconnect = 1;\r\n    \/\/conn_opts.onSuccess = onConnect;\r\n    conn_opts.onFailure = onConnectFailure;\r\n    MQTTAsync_setConnected(client, client, conn_established);\r\n\r\n    \/* \u5f00\u59cb\u8fde\u63a5 *\/\r\n    if ((rc = MQTTAsync_connect(client, &conn_opts)) != MQTTASYNC_SUCCESS)\r\n    {\r\n        printf(\"\u5f00\u59cb\u8fde\u63a5\u5931\u8d25\uff0c\u8fd4\u56de\u7801 %d\\n\", rc);\r\n        return EXIT_FAILURE;\r\n    }\r\n\r\n    while (!finished)\r\n    {\r\n        #if defined(_WIN32)\r\n            Sleep(1000);\r\n        #else\r\n            sleep(1);\r\n        #endif\r\n    }\r\n\r\n    if (subscribed)\r\n    {\r\n        if ((rc = MQTTAsync_unsubscribe(client, TOPIC, NULL)) != MQTTASYNC_SUCCESS)\r\n        {\r\n            printf(\"\u53d6\u6d88\u8ba2\u9605\u5931\u8d25\uff0c\u8fd4\u56de\u7801 %d\\n\", rc);\r\n            return EXIT_FAILURE;\r\n        }\r\n    }\r\n    \r\n    \/* \u65ad\u5f00\u8fde\u63a5 *\/\r\n    MQTTAsync_disconnectOptions disc_opts = MQTTAsync_disconnectOptions_initializer;\r\n    disc_opts.onSuccess = onDisconnect;\r\n    if ((rc = MQTTAsync_disconnect(client, &disc_opts)) != MQTTASYNC_SUCCESS)\r\n    {\r\n        printf(\"\u5f00\u59cb\u65ad\u5f00\u8fde\u63a5\u5931\u8d25\uff0c\u8fd4\u56de\u7801 %d\\n\", rc);\r\n        return EXIT_FAILURE;\r\n    }\r\n    while (!disc_finished)\r\n    {\r\n        #if defined(_WIN32)\r\n            Sleep(1000);\r\n        #else\r\n            sleep(1);\r\n        #endif\r\n    }\r\n\r\n    \/* \u9500\u6bc1\u5ba2\u6237\u7aef *\/\r\n    MQTTAsync_destroy(&client);\r\n\r\n    return EXIT_SUCCESS;\r\n}\r\n\n```\n\r\n\r\n \n\n---\n*modbus.cn*\n"