Qt 错误解决：QMetaObject::connectSlotsByName: No matching signal for on_modeComboBox_currentIndexChanged(int)

#include #include #include #include #include #include "sqlite.h"

Sqlite::Sqlite() {

}

void Sqlite::sqlite_init() { // 先关闭重复的数据库连接 if (QSqlDatabase::contains("qt_sql_default_connection")) { QSqlDatabase::removeDatabase("qt_sql_default_connection"); } QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE"); db.setDatabaseName("../Smarthome_Client/database/database.db"); if(!db.open()) { qDebug() << "无法打开数据库！"; } else{ qDebug() << "数据库打开成功！"; } }

// 更新智能家居状态表中的数据 void updateSmartHomeStatus(int userId, QString deviceName, QString devicestate, QString newValue) { Sqlite::sqlite_init(); // 执行更新操作 QSqlQuery query; query.prepare("SELECT * FROM Status WHERE uid = :userId"); query.bindValue(":userId", userId); if (!query.exec()) { qDebug() << "查询id失败：" << query.lastError().text(); } QString sql = QString("INSERT INTO Status (uid, device_name, device_state, value) VALUES (%1, '%2', '%3', '%4')") .arg(userId).arg(deviceName).arg(devicestate).arg(newValue); query.prepare(sql); if (!query.exec()) { qDebug() << "插入数据失败：" << query.lastError().text(); return; } }

boolean statusUid(int userId) { Sqlite::sqlite_init(); QSqlQuery query; // 查询智能家居状态表，获取用户对应的状态 query.prepare("SELECT * FROM status WHERE user_id = :userId"); query.bindValue(":userId", userId); qDebug() << query.exec(); if (!query.next()) { qDebug() << "Failed to execute query!" << query.lastError().text(); return false; }else{ qDebug() << "Successed to execute query!"; return true; } }

#ifndef USERSWIDGET_H #define USERSWIDGET_H

#include

namespace Ui { class UsersWidget; }

class UsersWidget : public QWidget { Q_OBJECT

public: explicit UsersWidget(int userid, QWidget *parent = nullptr); ~UsersWidget(); void displayUsersWidget();

protected: void closeEvent(QCloseEvent *);

signals: void modeChanged(const QString &mode); // 添加信号

private slots: void on_modeComboBox_currentIndexChanged(int index);

private: Ui::UsersWidget *ui; int userid; };

#endif // USERSWIDGET_H

#include "userswidget.h" #include "ui_userswidget.h" #include "sqlite.h" #include "lights.h" #include "aircondition.h" #include "curtains.h" #include "humidiffer.h" #include "information.h" #include "procession.h" #include "QCloseEvent" #include "QComboBox" #include "QMessageBox"

UsersWidget::UsersWidget(int userid, QWidget *parent) : QWidget(parent), ui(new Ui::UsersWidget) { ui->setupUi(this); displayUsersWidget(); connect(ui->lights, &QToolButton::clicked, this, [=]{ Lights *w = new Lights(userid); w->show(); }); connect(ui->air_condition, &QToolButton::clicked, this, [=]{ AirCondition *w = new AirCondition(userid); w->show(); }); connect(ui->curtains, &QToolButton::clicked, this, [=]{ Curtains *w = new Curtains(userid); w->show(); }); connect(ui->humidifiers, &QToolButton::clicked, this, [=]{ Humidiffer *w = new Humidiffer(userid); w->show(); }); connect(ui->tables, &QToolButton::clicked, this, [=]{ Information *w = new Information; w->show(); }); connect(ui->wifi, &QToolButton::clicked, this, [=]{ Procession *w = new Procession; w->show(); }); connect(ui->modeComboBox, QOverload::of(&QComboBox::currentIndexChanged), this, &UsersWidget::on_modeComboBox_currentIndexChanged);

}

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

void UsersWidget::displayUsersWidget() { setWindowTitle("智能家居总览图"); setFixedSize(900, 600);

}

void UsersWidget::on_modeComboBox_currentIndexChanged(int mode) { switch (mode) { case 1: { updateSmartHomeStatus(userid, "智能灯", "开启", "20"); updateSmartHomeStatus(userid, "空调", "开启", "27"); updateSmartHomeStatus(userid, "加湿器", "开启", "50"); updateSmartHomeStatus(userid, "窗帘", "开启", "100"); break; } case 2: { updateSmartHomeStatus(userid, "智能灯", "开启", "20"); updateSmartHomeStatus(userid, "空调", "开启", "27"); updateSmartHomeStatus(userid, "加湿器", "开启", "50"); updateSmartHomeStatus(userid, "窗帘", "开启", "100"); break; } case 3: { updateSmartHomeStatus(userid, "智能灯", "开启", "50"); updateSmartHomeStatus(userid, "空调", "开启", "26"); updateSmartHomeStatus(userid, "加湿器", "开启", "40"); updateSmartHomeStatus(userid, "窗帘", "开启", "30"); break; } default: ;

}

void UsersWidget::closeEvent(QCloseEvent *e) { if (e->spontaneous()) { //窗口关闭时弹出的提示窗口 QMessageBox::StandardButton reply;

    reply = QMessageBox::information(this, "提示", "确认退出智能管家系统？", QMessageBox::Yes | QMessageBox::No);
    if (reply == QMessageBox::Yes){
        //若用户点击确认，则接收这个事件,当前窗口会关闭
        e->accept();
     }else{
        //若用户点击取消，则忽略这个事件，当前窗口不会关闭
        e->ignore();
    }
}

}

#include #include #include #include #include #include "sqlite.h"

Sqlite::Sqlite() {

}

boolean statusUid(int userId) { Sqlite::sqlite_init(); QSqlQuery query; // 查询智能家居状态表，获取用户对应的状态 query.prepare("SELECT * FROM status WHERE uid = :userId"); query.bindValue(":userId", userId); qDebug() << query.exec(); if (!query.next()) { qDebug() << "Failed to execute query!" << query.lastError().text(); return false; }else{ qDebug() << "Successed to execute query!"; return true; } }

-- 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) );

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

SELECT device_state FROM Status WHERE uid = 123 AND device_name = '智能灯'; SELECT device_state FROM Status WHERE uid = 123 AND device_name = '智能灯' ORDER BY sid DESC LIMIT 1; UPDATE Status SET value = '12' , device_state = '开启' WHERE uid = 123 AND device_name = '智能灯';

Qt 错误解决：QMetaObject::connectSlotsByName: No matching signal for on_modeComboBox_currentIndexChanged(int)