1.qmqtt是一个Qt的MQTT客户端协议库，可以进行mqtt客户端的开发，下载地址是:https://github.com/emqx/qmqtt
2.下载出来的是源码，使用的话需要自己编译，请使用qt5.3及以上版本编译，在windows平台的话还得指定CONFIG += NO_UNIT_TESTS；如果要支持websocket的话请使用qt5.7及以上版本，同时需要配置CONFIG += QMQTT_WEBSOCKETS
3.打开工程文件，选择src执行qmake，然后点击构建即可生成相应的库文件
.
4.将四个库文件和所有的头文件整理到新建的两个lib和include件夹中如下
5.新建qt工程hellomqtt，将上一步建立的两个文件夹拷贝到新的工程目录下，并在qt中添加qmqtt库
6.程序代码见下
《1》hellomqtt.pro文件
#------------------------------------------------- # # Project created by QtCreator 2019-08-06T22:00:37 # #------------------------------------------------- QT += core gui network CONFIG += c++11 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TARGET = hellomqtt TEMPLATE = app # The following define makes your compiler emit warnings if you use # any feature of Qt which as been marked as deprecated (the exact warnings # depend on your compiler). Please consult the documentation of the # deprecated API in order to know how to port your code away from it. DEFINES += QT_DEPRECATED_WARNINGS # You can also make your code fail to compile if you use deprecated APIs. # In order to do so, uncomment the following line. # You can also select to disable deprecated APIs only up to a certain version of Qt. #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0 SOURCES += \ main.cpp \ mainwindow.cpp HEADERS += \ mainwindow.h FORMS += \ mainwindow.ui win32:CONFIG(release, debug|release): LIBS += -L$$PWD/lib/ -lqmqtt else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/lib/ -lqmqttd INCLUDEPATH += $$PWD/include DEPENDPATH += $$PWD/include win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/lib/libqmqtt.a else:win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/lib/libqmqttd.a else:win32:!win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/lib/qmqtt.lib else:win32:!win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/lib/qmqttd.lib
《2》mainwindow.h文件
#ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> #include "qmqtt.h" #include<QDebug> using namespace QMQTT; namespace Ui { class MainWindow; } class MainWindow : public QMainWindow { Q_OBJECT public: explicit MainWindow(QWidget *parent = 0); ~MainWindow(); private slots: void on_pb_connect_clicked(); void on_pushButton_clicked(); void on_pushButton_2_clicked(); void on_pushButton_3_clicked(); private: Ui::MainWindow *ui; QMQTT::Client *client; //MQTT客户端指针 public slots: void doConnected(); //MQTT 连接成功 void doDisconnected();//MQTT连接断开 void doDataReceived(QMQTT::Message);//MQTT收到数据 }; #endif // MAINWINDOW_H
《3》mainwindow.cpp文件
1 #include "mainwindow.h" 2 #include "ui_mainwindow.h" 3 4 #include<qnetwork.h> 5 6 MainWindow::MainWindow(QWidget *parent) : 7 QMainWindow(parent), 8 ui(new Ui::MainWindow) 9 { 10 ui->setupUi(this); 11 // QMQTT::Client *client = new QMQTT::Client(QHostAddress::LocalHost,11883); 12 //client = new QMQTT::Client(QHostAddress("127.0.0.1"),11883);//emqtt测试服务器 13 client = new QMQTT::Client(QHostAddress("192.168.1.10"),1883); 14 client->setClientId("clientid"); 15 client->setUsername("user"); 16 client->setPassword("password"); 17 ui->pushButton->setEnabled(false); 18 ui->pushButton_2->setEnabled(false); 19 connect(client,SIGNAL(connected()),this,SLOT(doConnected())); 20 connect(client,SIGNAL(disconnected()),this,SLOT(doDisconnected())); 21 connect(client,SIGNAL(received(QMQTT::Message)),this,SLOT(doDataReceived(QMQTT::Message))); 22 23 } 24 25 MainWindow::~MainWindow() 26 { 27 delete ui; 28 } 29 30 void MainWindow::on_pb_connect_clicked() 31 { 32 33 if(!client->isConnectedToHost()) 34 { 35 client->connectToHost(); 36 } 37 else { 38 client->disconnectFromHost(); 39 } 40 41 } 42 43 void MainWindow::doConnected() 44 { 45 ui->rb_status->setChecked(true); 46 ui->pb_connect->setText("Disconnect"); 47 ui->pushButton->setEnabled(true); 48 ui->pushButton_2->setEnabled(true); 49 } 50 51 void MainWindow::doDisconnected() 52 { 53 ui->rb_status->setChecked(false); 54 ui->pb_connect->setText("Connect"); 55 ui->pushButton->setEnabled(false); 56 ui->pushButton_2->setEnabled(false); 57 } 58 59 void MainWindow::doDataReceived(Message message) 60 { 61 QString mes = QString(message.id())+" "+QString(message.qos())+" "+message.topic()+" "+message.payload()+"\n"; 62 ui->te_log->append(mes); 63 } 64 65 66 void MainWindow::on_pushButton_clicked() 67 { 68 QString topic = ui->le_pb_topic->text().trimmed(); 69 QString payload = ui->le_pu_payload->text().trimmed(); 70 if(topic.isEmpty() || payload.isEmpty()) 71 { 72 qDebug()<<"pub topic and payload is empty!"<<endl; 73 return; 74 } 75 QMQTT::Message message(136,topic,payload.toUtf8()); 76 77 client->publish(message); 78 } 79 80 void MainWindow::on_pushButton_2_clicked() 81 { 82 QString topic = ui->le_sub_topic->text().trimmed(); 83 if(topic.isEmpty()) 84 { 85 qDebug()<<"sub topic and payload is empty!"<<endl; 86 return; 87 } 88 qDebug()<<topic<<endl; 89 client->subscribe(topic); 90 } 91 92 void MainWindow::on_pushButton_3_clicked() 93 { 94 QString topic = ui->le_sub_topic->text().trimmed(); 95 if(topic.isEmpty()) 96 { 97 qDebug()<<"sub topic and payload is empty!"<<endl; 98 return; 99 } 100 client->unsubscribe(topic); 101 102 }
《4》main.cpp文件
#include "mainwindow.h" #include <QApplication> int main(int argc, char *argv[]) { QApplication a(argc, argv); MainWindow w; w.show(); return a.exec(); }
《5》mainwindow.ui文件
<?xml version="1.0" encoding="UTF-8"?> <ui version="4.0"> <class>MainWindow</class> <widget class="QMainWindow" name="MainWindow"> <property name="geometry"> <rect> <x>0</x> <y>0</y> <width>400</width> <height>300</height> </rect> </property> <property name="windowTitle"> <string>MainWindow</string> </property> <widget class="QWidget" name="centralWidget"> <layout class="QVBoxLayout" name="verticalLayout_3"> <item> <layout class="QHBoxLayout" name="horizontalLayout_5"> <item> <widget class="QRadioButton" name="rb_status"> <property name="text"> <string>连接状态</string> </property> </widget> </item> <item> <widget class="QPushButton" name="pb_connect"> <property name="text"> <string>Connect</string> </property> </widget> </item> </layout> </item> <item> <layout class="QHBoxLayout" name="horizontalLayout_3"> <item> <layout class="QVBoxLayout" name="verticalLayout"> <item> <layout class="QHBoxLayout" name="horizontalLayout"> <item> <widget class="QLabel" name="label"> <property name="text"> <string>Topic：</string> </property> </widget> </item> <item> <widget class="QLineEdit" name="le_pb_topic"/> </item> </layout> </item> <item> <layout class="QHBoxLayout" name="horizontalLayout_2"> <item> <widget class="QLabel" name="label_2"> <property name="text"> <string>Payload:</string> </property> </widget> </item> <item> <widget class="QLineEdit" name="le_pu_payload"/> </item> </layout> </item> </layout> </item> <item> <widget class="QPushButton" name="pushButton"> <property name="text"> <string>Publish</string> </property> </widget> </item> </layout> </item> <item> <layout class="QHBoxLayout" name="horizontalLayout_4"> <item> <widget class="QLabel" name="label_3"> <property name="text"> <string>Topic:</string> </property> </widget> </item> <item> <widget class="QLineEdit" name="le_sub_topic"/> </item> <item> <widget class="QPushButton" name="pushButton_2"> <property name="text"> <string>Subscribe</string> </property> </widget> </item> <item> <widget class="QPushButton" name="pushButton_3"> <property name="text"> <string>UnSubscribe</string> </property> </widget> </item> </layout> </item> <item> <layout class="QVBoxLayout" name="verticalLayout_2"> <item> <widget class="QLabel" name="label_4"> <property name="text"> <string>LOG:</string> </property> </widget> </item> <item> <widget class="QTextBrowser" name="te_log"/> </item> </layout> </item> </layout> </widget> <widget class="QMenuBar" name="menuBar"> <property name="geometry"> <rect> <x>0</x> <y>0</y> <width>400</width> <height>23</height> </rect> </property> </widget> <widget class="QToolBar" name="mainToolBar"> <attribute name="toolBarArea"> <enum>TopToolBarArea</enum> </attribute> <attribute name="toolBarBreak"> <bool>false</bool> </attribute> </widget> <widget class="QStatusBar" name="statusBar"/> </widget> <layoutdefault spacing="6" margin="11"/> <resources/> <connections/> </ui>
7.编译和运行程序，经过测试，可以实现发布和订阅主题
MQTT协议文档下载地址：javascript:void(0)
qmqtt下载库：javascript:void(0)
基于QT的MQTT客户端工具源码：javascript:void(0)
modbus_TCP转MQTT协议源码：javascript:void(0)
MQTT-V5版本协议大全：javascript:void(0)
