QT DAY6作业

2026/8/7 14:09:54 拓冰建站浏览量

1.学生管理系统，基于QT的数据库中数据表的增删改查

头文件

#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>
#include <QSqlDatabase>  //数据库管理类
#include <QSqlQuery>   //执行sql语句类
#include <QSqlRecord>  //数据库记录类
#include <QSqlError>  //数据库错误类
#include <QMessageBox>  //消息对话框类namespace Ui {
class Widget;
}class Widget : public QWidget
{Q_OBJECTpublic:explicit Widget(QWidget *parent = nullptr);~Widget();private slots:void on_addBtn_clicked();void on_showBtn_clicked();void on_deleteBtn_clicked();void on_updateBtn_clicked();private:Ui::Widget *ui;//实例化一个数据库QSqlDatabase db;
};#endif // WIDGET_H

源文件

#include "widget.h"
#include "ui_widget.h"Widget::Widget(QWidget *parent) :QWidget(parent),ui(new Ui::Widget)
{ui->setupUi(this);//判断数据库是否存在if(!db.contains("stuInfo.db")){//说明数据库不存在，则创建db = QSqlDatabase::addDatabase("QSQLITE"); //增加一个数据库，驱动为sqlite3//给刚刚创建的数据库命名db.setDatabaseName("stuInfo");}//打开数据库if(!db.open()){QMessageBox::information(this,"","打开数据库失败");return;}//创建数据表//实例化一个执行sql语句的对象QSqlQuery query;//准备sql语句QString sql = "create table if not exists stu_info_table(""id integer primary key autoincrement,""numb int,""name char(20),""sex char(4),""score int)";//执行sql语句if(query.exec(sql)){QMessageBox::information(this,"","创建数据库表成功");}else {QMessageBox::information(this,"","创建数据库表失败");}}Widget::~Widget()
{delete ui;
}//添加按钮对应的槽函数处理
void Widget::on_addBtn_clicked()
{//获取ui界面上学生信息int numb = ui->numbEdit->text().toUInt();QString name = ui->nameEdit->text();QString sex = ui->sexEdit->text();int score = ui->scoreEdit->text().toUInt();//判断用户是否填写完整信息if(numb == 0 || name.isEmpty() || sex.isEmpty() || score == 0){QMessageBox::information(this,"","请将信息填写完整");return;}//实例化一个执行sql语句的对象QSqlQuery query;//准备sql语句QString sql = QString("insert into stu_info_table(numb,name,sex,score) ""values(%1,'%2','%3',%4)").arg(numb).arg(name).arg(sex).arg(score);//执行sql语句if(query.exec(sql)){QMessageBox::information(this,"","添加成功");ui->numbEdit->clear();ui->nameEdit->clear();ui->sexEdit->clear();ui->scoreEdit->clear();}else {QMessageBox::information(this,"","添加失败");}
}//显示按钮对应的槽函数处理
void Widget::on_showBtn_clicked()
{//实例化执行sql语句的对象QSqlQuery query;//准备sql语句QString sql = "select * from stu_info_table";//执行sql语句if(!query.exec(sql)){QMessageBox::information(this,"","查询失败");return;}//所查询的信息就已经存放到query对象中int i = 0; //记录行号while(query.next()){for(int j=0; j<query.record().count();j++)  //遍历列数{//将数据的数据放入ui界面ui->tableWidget->setItem(i,j,new QTableWidgetItem(query.value(j+1).toString()));}i++;  //行数递增}
}//删除按钮对应的槽函数处理
void Widget::on_deleteBtn_clicked()
{//实例化执行对象QSqlQuery query;//获取ui界面上的删除关键词int numb = ui->numbEdit->text().toUInt();if(numb == 0){QMessageBox::information(this,"","请输入删除学生学号");return;}//准备sql语句QString sql = QString("delete from stu_info_table where numb = %1").arg(numb);//执行sql语句if(query.exec(sql)){QMessageBox::information(this,"","删除成功");ui->numbEdit->clear();ui->tableEdit->clearcontens();}else {QMessageBox::information(this,"","删除失败");}
}//修改按钮对应的槽函数处理
void Widget::on_updateBtn_clicked()
{//实例化执行对象QSqlQuery query;//获取修改信息int numb = ui->numbEdit->text().toUInt();QString name = ui->nameEdit->text();QString sex = ui->sexEdit->text();int score = ui->scoreEdit->text().toUInt();if(numb == 0){QMessageBox::information(this,"","请输入修改学生学号");return;}if(!name.isEmpty()){//准备sql语句QString sql = QString("update stu_info_table set name = '%1' where numb = %2").arg(name).arg(numb);//执行sql语句if(query.exec(sql)){QMessageBox::information(this,"","修改成功");ui->numbEdit->clear();}else {QMessageBox::information(this,"","修改失败");}ui->nameEdit->clear();}if(!sex.isEmpty()){//准备sql语句QString sql = QString("update stu_info_table set sex = '%1' where numb = %2").arg(sex).arg(numb);//执行sql语句if(query.exec(sql)){QMessageBox::information(this,"","修改成功");ui->numbEdit->clear();}else {QMessageBox::information(this,"","修改失败");}ui->sexEdit->clear();}if(score != 0){//准备sql语句QString sql = QString("update stu_info_table set score = %1 where numb = %2").arg(score).arg(numb);//执行sql语句if(query.exec(sql)){QMessageBox::information(this,"","修改成功");ui->numbEdit->clear();}else {QMessageBox::information(this,"","修改失败");}ui->scoreEdit->clear();}
}

修改效果图

删除效果图

2.MP4视频的灰度显示和均衡模式

源文件

#include "widget.h"
#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);Widget w;w.show();//将本地的视频加载到程序中VideoCapture v;v.open("D:\\opencv\\heads\\01.mp4");//定义一个存放从视频中读取到的一帧图像Mat src;while(v.read(src)){//显示原图图像imshow("test1",src);//显示灰度图像//定义一个容器存放灰度图片Mat gray;//设置灰度cvtColor(src,gray,CV_BGR2GRAY);//显示灰度图像imshow("test2",gray);//显示均衡模式//定义一个容器存放均衡模式Mat dst;//均衡处理equalizeHist(gray,dst);//显示均衡图片imshow("test3",dst);if(waitKey(30) == 27){break;}}return a.exec();
}

效果图

3.思维导图

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QT DAY6作业