QT采用MQTT协议远程控制LED灯

测试环境：

mqtt_client(Publish) QT 5.6.0 win10

mqtt_client(Subscribe) ubuntu 12.04

mqtt_broker mosquitto ubuntu 12.0.4

开发QT程序使用了QMQTT library 下载地址

效果：

QT Client代码：

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "qmqtt.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QMQTT::Client *_client;
private slots:
    void onConnect();
    void onDisconnect();
    void ledonSlot();
    void ledoffSlot();
    void adjustLightNess();
};

#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QString>
#include <QDebug>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ui->luxHorizontalSlider->setMinimum(0);
    ui->luxHorizontalSlider->setMaximum(100);
    _client = new QMQTT::Client();
    QObject::connect(ui->connectBtn,SIGNAL(clicked(bool)),this,SLOT(onConnect()));
    QObject::connect(ui->disconnectBtn,SIGNAL(clicked(bool)),this,SLOT(onDisconnect()));
    QObject::connect(ui->ledOnBtn,SIGNAL(clicked(bool)),this,SLOT(ledonSlot()));
    QObject::connect(ui->ledOffBtn,SIGNAL(clicked(bool)),this,SLOT(ledoffSlot()));
    QObject::connect(ui->luxHorizontalSlider,SIGNAL(valueChanged(int)),this,SLOT(adjustLightNess()));
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::onConnect()
{
    QHostAddress host("127.0.0.1");
    quint16 port = 1883;
    _client->setHost(host);
    _client->setPort(port);
    _client->setClientId("client_id_1");
    _client->setUsername("sagarfan");
    _client->setPassword("password");
    _client->connectToHost();
    if(_client->isConnectedToHost())
    {
        ui->statusTextEdit->setText("connected");
    }
}

void MainWindow::onDisconnect()
{
    if(_client->isConnectedToHost())
    {
        _client->disconnectFromHost();
        ui->statusTextEdit->setText("disconnected");
    }
}

void MainWindow::ledonSlot()
{
    QString payload = "{\"cmd\":1}";
    qDebug() << payload;
    QMQTT::Message msg(0,"cmd",payload.toLatin1());
    if(_client->isConnectedToHost())
    {
        _client->publish(msg);
    }
    else
    {
        qDebug() << "not connected";
    }
}

void MainWindow::ledoffSlot()
{
    QString payload("{\"cmd\":0}");
    qDebug() << payload;
    QMQTT::Message msg(0,"cmd",payload.toLatin1());
    if(_client->isConnectedToHost())
    {
        _client->publish(msg);
    }
    else
    {
        qDebug() << "not connected";
    }
}

void MainWindow::adjustLightNess()
{
    QString tmp = "\"lux\":";
    QString postfix;
    postfix = QString::number(ui->luxHorizontalSlider->value());
    qDebug() << ui->luxHorizontalSlider->value();
    tmp += postfix;
    tmp += "}";
    QString prefix("{\"cmd\":3,");
    QString payload(prefix+tmp);

    qDebug() << payload;
    QMQTT::Message msg(0,"cmd",payload.toLatin1());
    if(_client->isConnectedToHost())
    {
        _client->publish(msg);
    }
    else
    {
        qDebug() << "not connected";
    }
}

main.cpp

#include <QApplication>
#include "mainwindow.h"
#include "qmqtt.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}