artistform.cpp

Qt4的一些例子

#include <QtGui>
#include <QtSql>

#include "artistform.h"
#include "generateid.h"

ArtistForm::ArtistForm(const QString &name, QWidget *parent)
    : QDialog(parent)
{
    model = new QSqlTableModel(this);
    model->setTable("artist");
    model->setSort(Artist_Name, Qt::AscendingOrder);
    model->setHeaderData(Artist_Name, Qt::Horizontal, tr("Name"));
    model->setHeaderData(Artist_Country, Qt::Horizontal, tr("Country"));
    model->select();
    connect(model, SIGNAL(beforeInsert(QSqlRecord &)),
            this, SLOT(beforeInsertArtist(QSqlRecord &)));

    tableView = new QTableView;
    tableView->setModel(model);
    tableView->setColumnHidden(Artist_Id, true);
    tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    tableView->resizeColumnsToContents();

    for (int row = 0; row < model->rowCount(); ++row) {
        QSqlRecord record = model->record(row);
        if (record.value(Artist_Name).toString() == name) {
            tableView->selectRow(row);
            break;
        }
    }

    addButton = new QPushButton(tr("&Add"));
    deleteButton = new QPushButton(tr("&Delete"));
    closeButton = new QPushButton(tr("Close"));
    connect(addButton, SIGNAL(clicked()), this, SLOT(addArtist()));
    connect(deleteButton, SIGNAL(clicked()),
            this, SLOT(deleteArtist()));
    connect(closeButton, SIGNAL(clicked()), this, SLOT(accept()));

    QHBoxLayout *buttonLayout = new QHBoxLayout;
    buttonLayout->addWidget(addButton);
    buttonLayout->addWidget(deleteButton);
    buttonLayout->addStretch();
    buttonLayout->addWidget(closeButton);

    QVBoxLayout *mainLayout = new QVBoxLayout;
    mainLayout->addWidget(tableView);
    mainLayout->addLayout(buttonLayout);
    setLayout(mainLayout);

    setWindowTitle(tr("Edit Artists"));
}

void ArtistForm::addArtist()
{
    int row = model->rowCount();
    model->insertRow(row);
    QModelIndex index = model->index(row, Artist_Name);
    tableView->setCurrentIndex(index);
    tableView->edit(index);
}

void ArtistForm::beforeInsertArtist(QSqlRecord &record)
{
    record.setValue("id", generateId("artist"));
}

void ArtistForm::deleteArtist()
{
    tableView->setFocus();
    QModelIndex index = tableView->currentIndex();
    if (!index.isValid())
        return;
    QSqlRecord record = model->record(index.row());

    QSqlTableModel cdModel;
    cdModel.setTable("cd");
    cdModel.setFilter("artistid = " + record.value("id").toString());
    cdModel.select();
    if (cdModel.rowCount() == 0) {
        model->removeRow(tableView->currentIndex().row());
    } else {
        QMessageBox::information(this,
                tr("Delete Artist"),
                tr("Cannot delete %1 because there are CDs associated "
                   "with this artist in the collection.")
                .arg(record.value("name").toString()));
    }
}