VC MFC C++ MQTT VC编译MQTT VC调用MQTT dll eclipse-paho-mqtt

约定不等于承诺〃 2022-12-01 15:49 285阅读 0赞

[VC MFC C++ MQTT VC编译MQTT VC调用MQTT dll eclipse-paho-mqtt][VC MFC C_ MQTT VC_MQTT VC_MQTT dll eclipse-paho-mqtt]

[JS HTML Web端使用MQTT通讯测试][JS HTML Web_MQTT]

[Android Studio MQTT 使用测试 eclipse.paho.mqtt][Android Studio MQTT _ eclipse.paho.mqtt]

系统：Windows10 64位

开发环境：Visual Studio 2013 64位

MQTT源码库：eclipse-paho-mqtt-c-src-1.2.0

测试工具：MQTTBox

MQTT服务器：阿里云部署EMQX

VC MFC程序运行图示：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70][]

# 一、编译MQTT 生成dll lib #

1、下载MQTT源码库：eclipse-paho-mqtt-c-src

下载[github][]地址：[https://github.com/eclipse][github]

2、解压、使用Visual Studio编译出动态链接库

解压eclipse-paho-mqtt-c-src

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 1][]

3、使用Visual Studio编译dll/lib

打开目录eclipse-paho-mqtt-c-src-1.2.0\\Windows Build中的Paho C MQTT APIs.sln工程

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 2][]

使用VS菜单->生成->生成解决方案，来生成dll和lib，生成目录为eclipse-paho-mqtt-c-src-1.2.0\\Windows Build\\Debug

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 3][]

错误和失败的是带SSL的，需要电脑安装OPENSSL库才能编译，需要SSL需求的同学自己安装OPENSSL再编译

paho-mqtt3a ： 一般实际开发中就是使用这个，a表示的是异步消息推送（asynchronous）。

paho-mqtt3as ： as表示的是 异步+加密（asynchronous+OpenSSL）。

paho-mqtt3c ： c 表示的应该是同步（Synchronize），一般性能较差，是发送+等待模式。

paho-mqtt3cs ： 同上，增加了一个OpenSSL而已

带S的都需要OpenSSL才能编译，test工程也一样

我的电脑没安装OpenSSL，所以只生成了

paho-mqtt3a.dll

paho-mqtt3a.lib

paho-mqtt3c.dll

paho-mqtt3c.lib

一般使用足够了，保存关闭工程，以后编译还会用到。

# 二、调用dll lib编写VC MQTT客户端 #

1、新建MFC工程

选择MFC用户程序，向导中选择基于对话框，在共享dll中使用MFC

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 4][]

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2、设置链接和头文件

将eclipse-paho-mqtt-c-src-1.2.0\\src目录中所有文件复制到此工程目录中include目录中（新建）

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 6][]

在工程中创建一个MQTT筛选器，添加MQTTAsync.h和MQTTClient.h

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 7][]

将刚才生成的dll复制到工程目录Debug，将刚才生成的lib复制到工程目录工程源码目录中

在工程属性页添加lib链接库

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 8][]

3、设计界面

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 9][]

4、编写代码，以下只列出MQTT调用核心代码，界面控件的响应和控制就不列出了，只实现基础功能，后期再添加新功能

包含头文件

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 10][]

连接服务器代码

MQTT_Conn_opts = MQTTClient_connectOptions_initializer;
    	MQTT_Pubmsg = MQTTClient_message_initializer;
    	
    	int rc;
    	MQTTClient_create(&MQTT_Client, ServerAddStr, CLIENTID, MQTTCLIENT_PERSISTENCE_NONE, NULL);
    	MQTT_Conn_opts.keepAliveInterval = atoi(KeepAliveStr);
    	MQTT_Conn_opts.cleansession = 1;
    	MQTT_Conn_opts.username = UserName;
    	MQTT_Conn_opts.password = PassWord;
    
    	MQTTClient_setCallbacks(MQTT_Client, NULL, MQTT_ConnLost, MQTT_MsgArrvd, MQTT_Delivered);
    
    	if ((rc = MQTTClient_connect(MQTT_Client, &MQTT_Conn_opts)) != MQTTCLIENT_SUCCESS){
    		AfxMessageBox("Failed to connect");// , return code %d\n", rc);
    		return;
    	}
    	else{
    		printf("MQTT Server Connect OK  \n");
    		((CButton*)GetDlgItem(IDC_BUTTON_ConnectServer))->SetWindowText("断开连接");//填入文本框
    		GetDlgItem(IDC_BUTTON_SendMsg)->EnableWindow(TRUE);// 发布按钮有效
    	}

断开连接代码

// 断开连接
    void CMQTT_TestDlg::DisconnectConnect()
    {
    	MQTTClient_disconnect(MQTT_Client, 10000);
    	MQTTClient_destroy(&MQTT_Client);
    	((CButton*)GetDlgItem(IDC_BUTTON_ConnectServer))->SetWindowText("连接服务器");//填入文本框
    }

发送消息代码

// 发布消息按钮
    void CMQTT_TestDlg::OnBnClickedButtonSendmsg()
    {
    	int rc;
    	CString PublishStr, SendMsgStr;
    	((CEdit*)GetDlgItem(IDC_EDIT_Publish))->GetWindowText(PublishStr);//获取文本框内容
    	((CEdit*)GetDlgItem(IDC_EDIT_SendMsg))->GetWindowText(SendMsgStr);//获取文本框内容
    	char buff[2048];
    	memset(buff, 0, sizeof(buff));
    	strcpy_s(buff, sizeof(buff),SendMsgStr );
    	MQTT_Pubmsg.payload = buff;
    	MQTT_Pubmsg.payloadlen = strlen(buff);
    	MQTT_Pubmsg.qos = QOS;
    	MQTT_Pubmsg.retained = 0;
    	MQTTClient_publishMessage(MQTT_Client, PublishStr, &MQTT_Pubmsg, &MQTT_Token);
    	printf("Waiting for up to %d seconds for publication of %s\n"
    		"on topic %s for client with ClientID: %s\n",
    		(int)(TIMEOUT / 1000), SendMsgStr, PublishStr, CLIENTID);
    	rc = MQTTClient_waitForCompletion(MQTT_Client, MQTT_Token, TIMEOUT);
    	printf("Message with delivery token %d delivered\n", MQTT_Token);
    	while (deliveredtoken != MQTT_Token);
    }

订阅按钮代码

// 订阅按钮
    void CMQTT_TestDlg::OnBnClickedButtonSubscribe()
    {
    	/* 订阅多条
    	char *const topics[] = { (char*)"topics1","topics2" };
    	//rc = MQTTClient_unsubscribeMany(client, 2, topics);
    	*/
    	CString SubscribeStr;
    	((CEdit*)GetDlgItem(IDC_EDIT_SubscribeMsg))->GetWindowText(SubscribeStr);//获取文本框内容
    	if (SubscribeStr.GetLength() <= 0){
    		AfxMessageBox("请输入要订阅的消息");
    	}else{
    		if (MQTTClient_subscribe(MQTT_Client, SubscribeStr, QOS) == MQTTCLIENT_SUCCESS){
    			int n = m_SubscribeList.GetItemCount();//获取list里面有多少行
    			m_SubscribeList.InsertItem(n, SubscribeStr);//插入行
    			((CEdit*)GetDlgItem(IDC_EDIT_SubscribeMsg))->SetWindowText("");//填入文本框
    		}else{
    			AfxMessageBox("订阅失败");
    		}
    	}
    }

取消订阅代码

// 取消订阅按钮
    void CMQTT_TestDlg::OnBnClickedButtonUnsubscribe()
    {
    	//获取选中的行
    	int r = m_SubscribeList.GetSelectionMark();
    	if (m_SubscribeList.GetSelectedCount() != 0){
    		CString str = m_SubscribeList.GetItemText(r, 0);
    		
    		printf("取消订阅  第 %d 行  内容：%s\r\n", r,str);
    		if (MQTTClient_unsubscribe(MQTT_Client, str) == MQTTCLIENT_SUCCESS){
    			m_SubscribeList.DeleteItem(r);
    		}else{
    			AfxMessageBox("取消订阅失败");
    		}
    	}else{
    		AfxMessageBox("请在列表中选择要取消订阅的消息");
    	}
    }

消息已送达回调

void MQTT_Delivered(void *context, MQTTClient_deliveryToken dt)
    {
    	printf("Message with token value %d delivery confirmed\n", dt);
    	deliveredtoken = dt;
    }

消息到达回调

int MQTT_MsgArrvd(void *context, char *topicName, int topicLen, MQTTClient_message *message)
    {
    	CString RevMsg,LastRevMsg,TopicName,Msg;
    	int i;
    	char* payloadptr;
    	char buf[4096];
    	memset(buf, 0, sizeof(buf));
    	printf("Message arrived\n");
    	printf("     topic: %s\n", topicName);
    	printf("   message: ");
    	payloadptr = (char *)message->payload;
    	for (i = 0; i<message->payloadlen; i++){
    		buf[i] = *payloadptr++;
    		//putchar(*payloadptr++);
    	}
    	putchar('\n');
    	//memcpy(buf, payloadptr, message->payloadlen);
    	TopicName.Format("%s", topicName);
    	Msg.Format("%s", buf);
    	RevMsg = "\r\n收到 " + TopicName + " 的消息：" + Msg;
    	printf("dddddddddddd  %s\r\n", RevMsg);
    	CMQTT_TestDlg *pDlg = (CMQTT_TestDlg*)g_pDlg;
    	pDlg->AddMsgToMsgBox(RevMsg);
    
    	MQTTClient_freeMessage(&message);
    	MQTTClient_free(topicName);
    	return 1;
    }

服务器连接断开回调

void MQTT_ConnLost(void *context, char *cause)
    {
    	printf("\nConnection lost\n");
    	printf("     cause: %s\n", cause);
    }

[VC MFC C_ MQTT VC_MQTT VC_MQTT dll eclipse-paho-mqtt]: https://blog.csdn.net/cnicfhnui/article/details/108272834
[JS HTML Web_MQTT]: https://blog.csdn.net/cnicfhnui/article/details/108282471
[Android Studio MQTT _ eclipse.paho.mqtt]: https://blog.csdn.net/cnicfhnui/article/details/108334690
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[github]: https://github.com/eclipse
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