使行保持在QTableView中

这就是我所做的

• 始终选择一个项目，并且
• 搜索时使所选项目可见

该解决方案甚至更新颖，因为当从无可见项转到一些可见项时，将选择最近选择的项，而不仅仅是第一项。

首先，我向该类添加了一个QModelIndex lastModelIndex;私有成员MainWindow，并将其设置在SelectionChanged插槽中。请注意，模型索引是存储的，而不是代理索引。

void MainWindow::selectionChangedSlot(QItemSelection const & selected, QItemSelection const & /*deselected*/)
{
    if (selected.count() > 0)
    {
        QModelIndex index = selected.indexes().first();
        QModelIndex modelIndex = itemProxy->mapToSource(index);

        lastModelIndex = modelIndex;
    }
}

接下来，我添加了两种方法：ensureSelected()...

void MainWindow::ensureSelected(QItemSelectionModel * selectionModel, int const proxyCount)
{
    if (selectionModel->hasSelection())
    {
        // an item is currently selected - don't have to do anything
    }
    else if (proxyCount == 1)
    {
        // no item is currently selected, but there is exactly one item in the list - select it
        QModelIndex proxyIndex = itemProxy->index(0, 0);

        selectionModel->setCurrentIndex(proxyIndex, QItemSelectionModel::Select | QItemSelectionModel::Rows);
    }
    else if (proxyCount > 1)
    {
        // no item is currently selected, but there are several items in the list

        QModelIndex proxyIndex; // !isValid

        if (lastModelIndex.isValid())
        {
            // there's a most recently selected item - compute its index in the list
            proxyIndex = itemProxy->mapFromSource(lastModelIndex);
        }

        if (proxyIndex.isValid())
        {
            // the most recently selected item is in the list - select it
            proxyIndex =  proxyIndex.sibling(proxyIndex.row(), COLUMN_THIS);
        }
        else
        {
            // there's no most recently selected item or it is no longer in the list - select the first item
            proxyIndex = itemProxy->index(0, 0);
        }

        selectionModel->setCurrentIndex(proxyIndex, QItemSelectionModel::Select | QItemSelectionModel::Rows);
    }
    else
    {
        // There are no items in the list - cannot select anything.
    }
}

...和ensureVisible()：

void MainWindow::ensureVisible(QItemSelectionModel * selectionModel)
{
    if (selectionModel->hasSelection())
    {
        const QModelIndex index = ui->tableView->currentIndex();

        ui->tableView->scrollTo(index);
        ui->tableView->selectRow(index.row());
        ui->tableView->scrollTo(index);
    }
}

看起来很奇怪，我必须打scrollTo()两次电话，否则tableView不会滚动。

这些新方法的调用方式on_lineEditSearch_textChanged()如下：

void MainWindow::on_lineEditSearch_textChanged(const QString & text)
{
    itemProxy->setFilterFixedString(text);

    QItemSelectionModel * selectionModel = ui->tableView->selectionModel();

    int modelCount = itemModel->rowCount(); // number of items in the model
    int proxyCount = itemProxy->rowCount(); // number of items in tableview

    ensureSelected(selectionModel, proxyCount);

    ensureVisible(selectionModel);

    updateStatusBar();
}

请在Pastie上找到更新的完整源代码。