使用Qt Charts监控智能家居状态：温度和湿度变化趋势

简介

本文将介绍如何使用Qt Charts库来创建可视化界面，用于监控智能家居设备的状态，例如空调的温度和加湿器的湿度。我们将使用SQLite数据库来存储设备数据，并使用Qt Charts库将数据动态展示在折线图上。

代码实现cpp#include 'information.h'#include 'ui_information.h'#include 'sqlite.h'#include <QtCharts/QChartView>#include <QtCharts/QLineSeries>#include <QtCharts/QValueAxis>#include #include #include

Information::Information(QWidget *parent) : QWidget(parent), ui(new Ui::Information){ ui->setupUi(this); setWindowTitle('家居状态'); setFixedSize(600,400);

QVBoxLayout *layout = new QVBoxLayout(this); // 创建一个垂直布局对象

// 创建温度折线图    QtCharts::QChartView *temperatureChartView = new QtCharts::QChartView(this);    QtCharts::QLineSeries *temperatureSeries = new QtCharts::QLineSeries();

Sqlite::sqlite_init();    QSqlQuery temperatureQuery;    temperatureQuery.exec('SELECT value FROM Status WHERE device_name = \'空调\' AND device_state = \'开启\'');    while (temperatureQuery.next())    {        double temperature = temperatureQuery.value(0).toDouble();        temperatureSeries->append(temperatureSeries->count(), temperature);    }

QtCharts::QChart *temperatureChart = new QtCharts::QChart();    temperatureChart->addSeries(temperatureSeries);

QtCharts::QValueAxis *temperatureAxisY = new QtCharts::QValueAxis();    temperatureAxisY->setRange(-5, 42); // 设置纵坐标范围为-5~42    temperatureChart->addAxis(temperatureAxisY, Qt::AlignLeft);    temperatureSeries->attachAxis(temperatureAxisY);

temperatureChart->setTitle('空调温度变化表'); // 设置折线图名

temperatureChartView->setChart(temperatureChart);    temperatureChartView->setRenderHint(QPainter::Antialiasing);    temperatureChartView->setMinimumSize(800, 600);

layout->addWidget(temperatureChartView); // 使用布局对象的addWidget()函数添加chartView

// 创建湿度折线图    QtCharts::QChartView *humidityChartView = new QtCharts::QChartView(this);    QtCharts::QLineSeries *humiditySeries = new QtCharts::QLineSeries();

QSqlQuery humidityQuery;    humidityQuery.exec('SELECT value FROM Status WHERE device_name = \'加湿器\' AND device_state = \'开启\'');    while (humidityQuery.next())    {        double humidity = humidityQuery.value(0).toDouble();        humiditySeries->append(humiditySeries->count(), humidity);    }

QtCharts::QChart *humidityChart = new QtCharts::QChart();    humidityChart->addSeries(humiditySeries);

QtCharts::QValueAxis *humidityAxisY = new QtCharts::QValueAxis();    humidityAxisY->setRange(0, 100); // 设置纵坐标范围为0~100    humidityChart->addAxis(humidityAxisY, Qt::AlignLeft);    humiditySeries->attachAxis(humidityAxisY);

humidityChart->setTitle('加湿器湿度变化表'); // 设置折线图名

humidityChartView->setChart(humidityChart);    humidityChartView->setRenderHint(QPainter::Antialiasing);    humidityChartView->setMinimumSize(800, 600);

layout->addWidget(humidityChartView); // 使用布局对象的addWidget()函数添加chartView

setLayout(layout); // 将布局对象设置为窗口的布局}

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

数据库设计sql-- 创建用户表CREATE TABLE IF NOT EXISTS users ( uid INTEGER PRIMARY KEY AUTOINCREMENT, username varchar(10), passwd varchar(10));

-- 创建智能家居状态表CREATE TABLE IF NOT EXISTS Status ( sid INTEGER PRIMARY KEY AUTOINCREMENT, uid INTEGER , device_name varchar(10), device_state varchar(10), value varchar(10), mode varchar(10), FOREIGN KEY (uid) REFERENCES users (uid));

数据查询示例

以下是几个常用的数据查询语句：

• 查询智能灯的状态：sqlSELECT device_state FROM Status WHERE uid = 123 AND device_name = '智能灯';

• 查询智能灯的最新状态：sqlSELECT device_state FROM Status WHERE uid = 123 AND device_name = '智能灯' ORDER BY sid DESC LIMIT 1;

• 更新智能灯的状态和亮度：sqlUPDATE Status SET value = '12', device_state = '开启' WHERE uid = 123 AND device_name = '智能灯';

总结

本文介绍了如何使用Qt Charts库创建可视化界面来监控智能家居设备的状态，并提供了详细的代码示例和数据库设计。您可以根据自己的需求修改代码，添加更多类型的设备和状态监控功能。