QT-day6

作业1：数据库增删查改

#include "widget.h"
#include "ui_widget.h"Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);if (!db.contains("stu.db")){db = QSqlDatabase::addDatabase("QSQLITE");db.setDatabaseName("stuInfo");}if (!db.open()){QMessageBox::warning(this,"","打开数据库失败");return;}QSqlQuery query;QString sql = "create table if not exists stu_info_table(""id integer primary key autoincrement,""numb integer,""name varchar(20),""sex varchar(4),""score integer)";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;
}void Widget::on_btn_add_clicked()
{int numb = ui->edit_numb->text().toUInt();QString name = ui->edit_name->text();QString sex = ui->edit_sex->text();int score = ui->edit_score->text().toUInt();if (numb == 0 || name.isEmpty() || sex.isEmpty() || score == 0){QMessageBox::information(this,"","请填写完整");return;}QSqlQuery query;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);if (query.exec(sql)){QMessageBox::information(this,"","添加成功");}else{QMessageBox::information(this,"","添加失败");}
}void Widget::on_btn_show_clicked()
{ui->tableWidget->clear();QSqlQuery query;QString sql = "select * from stu_info_table";if (!query.exec(sql)){QMessageBox::information(this,"","查询失败");return;}int i = 0;//行号int j = 0;//列号while (query.next()){for (j = 0;j < query.record().count()-1;j++){ui->tableWidget->setItem(i,j,new QTableWidgetItem(query.value(j+1).toString()));}i++;}}void Widget::on_btn_del_clicked()
{QSqlQuery query;int numb = ui->edit_numb->text().toUInt();QString sql = QString("delete from stu_info_table where numb=%1").arg(numb);if (query.exec(sql)){QMessageBox::information(this,"","删除成功");}else{QMessageBox::information(this,"","删除失败");}
}void Widget::on_btn_update_clicked()
{QSqlQuery query;int numb = ui->edit_numb->text().toUInt();QString name = ui->edit_name->text();QString sex = ui->edit_sex->text();int score = ui->edit_score->text().toUInt();if (numb == 0 || name.isEmpty() || sex.isEmpty() || score == 0){QMessageBox::information(this,"","请填写完整");return;}QString sql = QString("update stu_info_table set name='%1',sex='%2',score=%3 where numb=%4").arg(name).arg(sex).arg(score).arg(numb);if (query.exec(sql)){QMessageBox::information(this,"","修改成功");}else{QMessageBox::information(this,"","修改失败");}
}

作业2：黑白

#include "widget.h"
#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);Widget w;w.show();VideoCapture v;v.open("D:\\opencv\\heads\\01.mp4");Mat src;Mat gray;while (v.read(src)){//imshow("test1",src);cvtColor(src,gray,CV_BGR2GRAY);imshow("test2",gray);if(waitKey(30) == 27){break;}}return a.exec();
}

思维导图