QSqlTableModel：我在哪里可以得到一行是否被标记为已删除

Question

如果我对从数据库中读取的记录调用 removeRows a !会显示在tableView的第一列。

我唯一想要实现的是该行不会显示在视图中。我用 QSortFilterProxyModel 试过了，但我不知道在哪里可以得到用于显示的标志！在第一列。有没有办法在 QSortFilterProxyModel 中设置一个过滤器，它只包含没有这个标志的行？

视图从哪里获取信息，删除的行标有“！” ？此信息可能隐藏在模型中的某处，但我找不到位置。

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent),
    m_ui(new Ui::MainWindow),
    m_model(new QSqlTableModel(this)),
    m_proxyModel(new QSortFilterProxyModel(this))
{
    m_ui->setupUi(this);
    m_model->setTable("test");
    m_model->setEditStrategy(QSqlTableModel::OnManualSubmit);
    m_model->select();

    m_proxyModel->setSourceModel(m_model);

    m_ui->tableView->setModel(m_proxyModel);

    qDebug() << "Select       : Row count:" << m_model->rowCount();

    connect(m_ui->tableView->selectionModel(), &QItemSelectionModel::selectionChanged,
            this, &MainWindow::on_selectionChanged);
}

MainWindow::~MainWindow()
{
    delete m_ui;
}

void MainWindow::on_pushButtonNewRecord_clicked()
{
    qDebug() << "New Record";

    m_record = m_model->record();
    m_record.setValue("firstname", "john");
    m_record.setValue("lastname", "doe");
    m_record.setValue("email", "john.doe@email.com");

    m_model->insertRecord(-1, m_record);

    qDebug() << "New Record   : Row count:" << m_model->rowCount();
}

void MainWindow::on_pushButtonRemoveRow_clicked()
{
    qDebug() << "Remove Row";

    if (m_row >= 0) {
        m_proxyModel->removeRow(m_row);

        qDebug() << "Remove Record: Row count:" << m_model->rowCount();
    }

    for (int i = 0; i < m_model->rowCount(); i++) {
        qDebug() << "\n";
        qDebug() << "Remove Row: index  :" << m_model->index(i, 0);
        qDebug() << "Remove Row: isValid:" << m_model->index(i, 0).isValid();
        qDebug() << "Remove Row: isDirty:" << m_model->isDirty(m_model->index(i, 0));
        qDebug() << "Remove Row: flags  :" << m_model->index(i, 0).flags();
        qDebug() << "Remove Row: data   :" << m_model->index(i, 0).data(Qt::DisplayRole);
        qDebug() << "Remove Row: heaader:" << m_model->headerData(i, Qt::Vertical);
        QVariant verticalHeader = m_model->headerData(i, Qt::Vertical);
        if (verticalHeader == "!") {
            qDebug() << "Deleted";
        }
        //qDebug() << m_model->record(i);
    }
}

void MainWindow::on_pushButtonSubmit_clicked()
{
    qDebug() << "Submit";

    m_model->submitAll();
    m_model->select();
}


void MainWindow::on_selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)
{
    Q_UNUSED(deselected)

    if (!selected.isEmpty()) {
        m_row = selected.indexes().first().row();
    }
}

Answer 1

您必须实现一个 QSortFilterProxyModel 来过滤 Dirty 行，其垂直 header 文本为“！”，您还必须调用 invalidate() 方法来强制应用过滤器.

dirtyfilterproxymodel.h

#ifndef DIRTYFILTERPROXYMODEL_H
#define DIRTYFILTERPROXYMODEL_H

#include <QSortFilterProxyModel>
#include <QSqlTableModel>

class DirtyFilterProxyModel : public QSortFilterProxyModel
{
public:
    using QSortFilterProxyModel::QSortFilterProxyModel;
protected:
    bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
    {
        if(QSqlTableModel *source_model = qobject_cast<QSqlTableModel *>(sourceModel())){
            QModelIndex ix = source_model->index(source_row, 0, source_parent);
            QString row_header_item = source_model->headerData(source_row, Qt::Vertical, Qt::DisplayRole).toString();
            return !(source_model->isDirty(ix) && row_header_item == QLatin1String("!"));
        }
        return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
    }
};

#endif // DIRTYFILTERPROXYMODEL_H

mainwindow.h

// ...
class DirtyFilterProxyModel;
// ...
class MainWindow : public QMainWindow
{
    // ...
private:
    Ui::MainWindow *m_ui;
    <b>DirtyFilterProxyModel *m_proxyModel;</b>
    // ...

mainwindow.cpp

<b>#include "dirtyfilterproxymodel.h"</b>
// ...
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent),
    m_ui(new Ui::MainWindow),
    m_model(new QSqlTableModel(this)),
    <b>m_proxyModel(new DirtyFilterProxyModel(this))</b>
{
    // ...
}

void MainWindow::on_pushButtonNewRecord_clicked()
{
    // ...
    m_model->insertRecord(-1, m_record);
    <b>m_proxyModel->invalidate()</b>;
}
// ...
void MainWindow::on_pushButtonRemoveRow_clicked()
{    if (m_row >= 0) {
        m_proxyModel->removeRow(m_row);
        <b>m_proxyModel->invalidate();</b>
    }
}

QSqlTableModel：我在哪里可以得到一行是否被标记为已删除

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