Qt操作主/从视图及XML——实例：汽车管理系统

1. 主界面布局

先创建一个QMainwindow，不带设计界面

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QGroupBox>
#include <QTableView>
#include <QListWidget>
#include <QLabel>


class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    //MainWindow(QWidget *parent = 0);
    MainWindow(QWidget *parent = 0);   //构造函数
    ~MainWindow();
private:
    QGroupBox *createCarGroupBox();
    QGroupBox *createFactoryGroupBox();
    QGroupBox *createDetailsGroupBox();
    void createMenuBar();
    QTableView *carView;						//(a)
    QTableView *factoryView;					//(b)
    QListWidget *attribList;					//显示车型的详细信息列表
    /* 声明相关的信息标签 */
    QLabel *profileLabel;
    QLabel *titleLabel;

};

#endif // MAINWINDOW_H

然后再在mainwindow.cpp中

#include "mainwindow.h"
#include <QGridLayout>
#include <QAbstractItemView>
#include <QHeaderView>
#include <QAction>
#include <QMenu>
#include <QMenuBar>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QGroupBox *factory = createFactoryGroupBox();
    QGroupBox *cars = createCarGroupBox();
    QGroupBox *details = createDetailsGroupBox();
    //布局
    QGridLayout *layout = new QGridLayout;
    layout->addWidget(factory, 0, 0);
    layout->addWidget(cars, 1, 0);
    layout->addWidget(details, 0, 1, 2, 1);
    layout->setColumnStretch(1, 1);
    layout->setColumnMinimumWidth(0, 500);
    QWidget *widget = new QWidget;
    widget->setLayout(layout);
    setCentralWidget(widget);
    createMenuBar();
    resize(850, 400);
    setWindowTitle(u8"主从视图");
}

QGroupBox* MainWindow::createFactoryGroupBox()
{
    factoryView = new QTableView;
    factoryView->setEditTriggers(QAbstractItemView::NoEditTriggers);
                                                            //(a)
    factoryView->setSortingEnabled(true);
    factoryView->setSelectionBehavior(QAbstractItemView::SelectRows);
    factoryView->setSelectionMode(QAbstractItemView::SingleSelection);
    factoryView->setShowGrid(false);
    factoryView->setAlternatingRowColors(true);
    QGroupBox *box = new QGroupBox(u8"汽车制造商");
    QGridLayout *layout = new QGridLayout;
    layout->addWidget(factoryView, 0, 0);
    box->setLayout(layout);
    return box;
}

QGroupBox* MainWindow::createCarGroupBox()
{
    QGroupBox *box = new QGroupBox(u8"汽车");
    carView = new QTableView;
    carView->setEditTriggers(QAbstractItemView::NoEditTriggers);
    carView->setSortingEnabled(true);
    carView->setSelectionBehavior(QAbstractItemView::SelectRows);
    carView->setSelectionMode(QAbstractItemView::SingleSelection);
    carView->setShowGrid(false);
    carView->verticalHeader()->hide();
    carView->setAlternatingRowColors(true);

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(carView, 0, 0);
    box->setLayout(layout);
    return box;
}

QGroupBox* MainWindow::createDetailsGroupBox()
{
    QGroupBox *box = new QGroupBox(u8"详细信息");
    profileLabel = new QLabel;
    profileLabel->setWordWrap(true);
    profileLabel->setAlignment(Qt::AlignBottom);
    titleLabel = new QLabel;
    titleLabel->setWordWrap(true);
    titleLabel->setAlignment(Qt::AlignBottom);
    attribList = new QListWidget;
    QGridLayout *layout = new QGridLayout;
    layout->addWidget(profileLabel, 0, 0, 1, 2);
    layout->addWidget(titleLabel, 1, 0, 1, 2);
    layout->addWidget(attribList, 2, 0, 1, 2);
    layout->setRowStretch(2, 1);
    box->setLayout(layout);
    return box;
}

void MainWindow::createMenuBar()
{
    QAction *addAction = new QAction(u8"添加", this);
    QAction *deleteAction = new QAction(u8"删除", this);
    QAction *quitAction = new QAction(u8"退出", this);
    addAction->setShortcut(tr("Ctrl+A"));
    deleteAction->setShortcut(tr("Ctrl+D"));
    quitAction->setShortcut(tr("Ctrl+Q"));
    QMenu *fileMenu = menuBar()->addMenu(u8"操作菜单");
    fileMenu->addAction(addAction);
    fileMenu->addAction(deleteAction);
    fileMenu->addSeparator();
    fileMenu->addAction(quitAction);
}


MainWindow::~MainWindow()
{

}

运行结果如图所示

2.连接数据库

改个名字项目结构更清晰一点

这边需要先添加最底层的GroupBox控件，数据库连接设置，再在上面添加别的

添加完控件之后需要将.ui文件生成.h文件
此处转换方法参考

uic connectdlg.ui -o ui_connectdlg.h

头文件connectdlg.h中

#ifndef CONNECTDLG_H
#define CONNECTDLG_H

#include <QDialog>
#include <QMessageBox>
#include "ui_connectdlg.h"
class QSqlError;

class ConnDlg : public QDialog
{
    Q_OBJECT

public:
    ConnDlg(QWidget *parent = 0);
    //~ConnDlg();
    QString driverName() const;
    QString databaseName() const;
    QString userName() const;
    QString password() const;
    QString hostName() const;
    int port() const;
    QSqlError addConnection(const QString &driver, const QString &dbName, const QString &host,const QString &user, const QString &passwd, int port = -1);
    void creatDB();
    void addSqliteConnection();
private slots:
    void on_okButton_clicked();
    void on_cancelButton_clicked() { reject(); }
    void driverChanged(const QString &);
private:
   Ui::QSqlConnectionDialogUi ui;
};

#endif // CONNECTDLG_H

connectdlg.cpp中

#include "connectdlg.h"
#include "ui_connectdlg.h"
#include <QSqlDatabase>
#include <QtSql>
#pragma execution_character_set("UTF-8")
ConnDlg::ConnDlg(QWidget *parent) :
    QDialog(parent)
{
    ui.setupUi(this);
    QStringList drivers = QSqlDatabase::drivers();		//(a)
    ui.comboDriver->addItems(drivers);					//(b)
    connect(ui.comboDriver,SIGNAL(currentIndexChanged(const QString &)),this,SLOT(driverChanged(const QString &)));	//(c)
    ui.status_label->setText(u8"准备连接数据库！");		//(d)
}
/*
ConnDlg::~ConnDlg()
{
    delete ui;
}
*/
void ConnDlg::driverChanged(const QString & text)
{
    if(text =="QSQLITE")								//(a)
    {
        ui.editDatabase->setEnabled(false);
        ui.editUsername->setEnabled(false);
        ui.editPassword->setEnabled(false);
        ui.editHostname->setEnabled(false);
        ui.portSpinBox->setEnabled(false);
    }
    else
    {
        ui.editDatabase->setEnabled(true);
        ui.editUsername->setEnabled(true);
        ui.editPassword->setEnabled(true);
        ui.editHostname->setEnabled(true);
        ui.portSpinBox->setEnabled(true);
    }
}
QString ConnDlg::driverName() const
{
      return ui.comboDriver->currentText();
}
QString ConnDlg::databaseName() const
{
     return ui.editDatabase->text();
}
QString ConnDlg::userName() const
{
     return ui.editUsername->text();
}
QString ConnDlg::password() const
{
    return ui.editPassword->text();
}
QString ConnDlg::hostName() const
{
    return ui.editHostname->text();
}
int ConnDlg::port() const
{
    return ui.portSpinBox->value();
}
void ConnDlg::on_okButton_clicked()
{
    if (ui.comboDriver->currentText().isEmpty())		//(a)
    {
        ui.status_label->setText(u8"请选择一个数据库驱动！");
        ui.comboDriver->setFocus();
    }
    else if(ui.comboDriver->currentText() =="QSQLITE")	//(b)
    {
        addSqliteConnection();
        //创建数据库表，如已存在则无须执行
        creatDB();                                      //(c)
        accept();
        }
    else
    {
        QSqlError err = addConnection(driverName(), databaseName(), hostName(),userName(), password(), port());				//(d)
        if (err.type() != QSqlError::NoError)           //(e)
            ui.status_label->setText(err.text());
        else											//(f)
            ui.status_label->setText(u8"连接数据库成功!");
        //创建数据库表，如已存在则无须执行
        accept();
    }
}
QSqlError ConnDlg::addConnection(const QString &driver, const QString &dbName, const QString &host,const QString &user, const QString &passwd, int port)
{
    QSqlError err;
    QSqlDatabase db = QSqlDatabase::addDatabase(driver);
    db.setDatabaseName(dbName);
    db.setHostName(host);
    db.setPort(port);
    if (!db.open(user, passwd))                         //(a)
    {
        err = db.lastError();
    }
    return err;                                         //返回这个错误信息
}
void ConnDlg::addSqliteConnection()
{
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName("databasefile");
    if (!db.open())
    {
        ui.status_label->setText(db.lastError().text());
        return;
    }
    ui.status_label->setText(u8"创建sqlite数据库成功!");
}
void ConnDlg::creatDB()
{
    QSqlQuery query;                                    //(a)
    query.exec("create table factory (id int primary key,manufactory varchar(40), address varchar(40))");				//(b)
    query.exec(QObject::tr("insert into factory values(1, '一汽大众', '长春')"));
    query.exec(QObject::tr("insert into factory values(2, '二汽神龙', '武汉')"));
    query.exec(QObject::tr("insert into factory values(3, '上海大众', '上海')"));
    query.exec("create table cars (carid int primary key, name varchar(50), factoryid int, year int, foreign key(factoryid) references factory(id))");	//(c)
    query.exec(QObject::tr("insert into cars values(1,'奥迪A6',1,2005)"));
    query.exec(QObject::tr("insert into cars values(2, '捷达', 1, 1993)"));
    query.exec(QObject::tr("insert into cars values(3, '宝来', 1, 2000)"));
    query.exec(QObject::tr("insert into cars values(4, '毕加索',2, 1999)"));
    query.exec(QObject::tr("insert into cars values(5, '富康', 2, 2004)"));
    query.exec(QObject::tr("insert into cars values(6, '标致307',2, 2001)"));
    query.exec(QObject::tr("insert into cars values(7, '桑塔纳',3, 1995)"));
    query.exec(QObject::tr("insert into cars values(8, '帕萨特',3, 2000)"));
}

3.主/从视图应用

完整的mainwindow.h代码
代码太多了，看资源绑定吧
新建一个xml文件

注意，xml文件路径，和python一样的，向右倒的

#define XML_FILE_PATH "D:/Qt_CH/CH13/CH1302/SQLEx/attribs.xml"

当我新添加一个时，发现xml文件里面也写进去了