Day6 Qt

思维导图

1.数据库增删改查

头文件widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include 
#include  //数据库管理类
#include   // 执行sql语句类
#include  //数据库记录类
#include  //
#include  //消息对话框类

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = nullptr);
    ~Widget();

private slots:
    void on_addBtn_clicked();

    void on_showBtn_clicked();

    void on_addBtn_2_clicked();

    void on_updatebtn_clicked();

private:
    Ui::Widget *ui;

    QSqlDatabase db;
};

#endif // WIDGET_H

2.widget.cpp

#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
        db = QSqlDatabase::addDatabase("QSQLITE");//增加一个数据库，驱动sqlite3
        db.setDatabaseName("stuInfo");
    }
    //打开数据库
    if(!db.open())
    {
        QMessageBox::information(this,"","打开数据库失败");
        return;
    }

    //创建数据库表
    //实例化执行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 integer,"
                  "name varchar(20),"
                  "sex varchar(4),"
                  "score integer)";
    //执行
    if(query.exec(sql))
    {
        QMessageBox::information(this,"","创建数据表成功");
    }else {
        QMessageBox::information(this,"","创建数据库表失败！");
    }
}

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

void Widget::on_addBtn_clicked()
{
    //获取UI界面学生信息
    int numb = ui->numberEdit->text().toUInt();

    QString name = ui->nameEdit->text();

    QString sex = ui->sexEdit->text();

    int score = ui->scroeEdit->text().toUInt();

    if(numb == 0 || name.isEmpty() || sex.isEmpty() || score ==0)
    {
        QMessageBox::information(this,"","请将信息填写完整");
        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_showBtn_clicked()
{
    QSqlQuery query;
    QString sql = "select * from stu_info_table";

    if(!query.exec(sql))
    {
        QMessageBox::information(this,"","查询失败");
        return;
    }

    int i = 0;
    while(query.next())
    {
        for (int j = 0;jtableWidget->setItem(i,j,new QTableWidgetItem(query.value(j+1).toString()));
        }
        i++;//行数递增
    }
}

void Widget::on_addBtn_2_clicked()
{
    QSqlQuery query;
    QString numb = ui->numberEdit->text();

    QString name = ui->nameEdit->text();

    QString sex = ui->sexEdit->text();

    QString score = ui->scroeEdit->text();
    if(!numb.isEmpty())
    {
        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 if(!name.isEmpty())
    {
        QString sql = QString("delete from stu_info_table where name='%1'").arg(name);
        if(query.exec(sql))
        {
            QMessageBox::information(this,"","删除成功");
        }
    }else if(!sex.isEmpty())
    {
        QString sql = QString("delete from stu_info_table where sex='%1'").arg(sex);
        if(query.exec(sql))
        {
            QMessageBox::information(this,"","删除成功");
        }
    }else if(!score.isEmpty())
    {
        QString sql = QString("delete from stu_info_table where score='%1'").arg(score);
        if(query.exec(sql))
        {
            QMessageBox::information(this,"","删除成功");
        }
    }


}

void Widget::on_updatebtn_clicked()
{
    int numb = ui->numberEdit->text().toUInt();
       QString name = ui->nameEdit->text();
       QString sex = ui->sexEdit->text();
       int score = ui->scroeEdit->text().toUInt();
       QSqlQuery query;
       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");
           return;
       }
}

视频处理

头文件

#ifndef WIDGET_H
#define WIDGET_H

#include 
#include 
#include 
#include 
#include
#include 
#include 

#include "widget.h"
#include 

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来

    VideoCapture v;

    v.open("D:\\opencv\\heads\\01.mp4");
    //定义一个存放从视频里读取到的一帧图像

    Mat src;
    Mat gray;
    Mat dst;
    while(v.read(src))
    {
        cvtColor(src,gray,CV_BGR2GRAY);
        equalizeHist(gray,dst);
        imshow("test2",gray);
        imshow("test1",src);
        imshow("test3",dst);
        if(waitKey(30)==27)
        {
            break;
        }
    }


    return a.exec();
}