从逗号分隔的文本文件创建自定义 QAbstractItemModel

Question

我有这个问题，我的 Qtableview 在插入 100.000 行并特别使用多选后变得非常缓慢。

所以经过一些研究后，我决定使用我自己的模型，该模型继承自 QAbstractItemModel。但问题是我不知道如何使用它，因为文本文件可以更改。外汇。我可以加载一个包含 5 列和 50.000 行的文件，一段时间后它可以有 15 列和 10.000 行。 数据不需要更改，因此它只是只读的。 谁能帮我解决这个问题？

我的“空”自定义模型在这里

#include "customabstractmodel.h"

CustomAbstractModel::CustomAbstractModel(QObject *parent)
    : QAbstractItemModel(parent)
{
}

QVariant CustomAbstractModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    // FIXME: Implement me!
}

bool CustomAbstractModel::setHeaderData(int section, Qt::Orientation orientation, const QVariant &value, int role)
{
    if (value != headerData(section, orientation, role)) {
        // FIXME: Implement me!
        emit headerDataChanged(orientation, section, section);
        return true;
    }
    return false;
}

QModelIndex CustomAbstractModel::index(int row, int column, const QModelIndex &parent) const
{
    // FIXME: Implement me!
}

QModelIndex CustomAbstractModel::parent(const QModelIndex &index) const
{
    // FIXME: Implement me!
}

int CustomAbstractModel::rowCount(const QModelIndex &parent) const
{
    if (!parent.isValid())
        return 0;

    // FIXME: Implement me!
}

int CustomAbstractModel::columnCount(const QModelIndex &parent) const
{
    if (!parent.isValid())
        return 0;

    // FIXME: Implement me!
}

QVariant CustomAbstractModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    // FIXME: Implement me!
    return QVariant();
}

bool CustomAbstractModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    if (data(index, role) != value) {
        // FIXME: Implement me!
        emit dataChanged(index, index, QVector<int>() << role);
        return true;
    }
    return false;
}

Qt::ItemFlags CustomAbstractModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;

    return Qt::ItemIsEditable; // FIXME: Implement me!
}

bool CustomAbstractModel::insertRows(int row, int count, const QModelIndex &parent)
{
    beginInsertRows(parent, row, row + count - 1);
    // FIXME: Implement me!
    endInsertRows();
}

bool CustomAbstractModel::insertColumns(int column, int count, const QModelIndex &parent)
{
    beginInsertColumns(parent, column, column + count - 1);
    // FIXME: Implement me!
    endInsertColumns();
}

bool CustomAbstractModel::removeRows(int row, int count, const QModelIndex &parent)
{
    beginRemoveRows(parent, row, row + count - 1);
    // FIXME: Implement me!
    endRemoveRows();
}

bool CustomAbstractModel::removeColumns(int column, int count, const QModelIndex &parent)
{
    beginRemoveColumns(parent, column, column + count - 1);
    // FIXME: Implement me!
    endRemoveColumns();
}

编辑 #1 Csv 数据（非真实信息，随机）

姓名、电话、电子邮件、地址、城市、邮编 Chavez, Lisandra F.,1-498-913-8181,ac.fermentum.vel@semperrutrumFusce.org,Ap #123-1044 Sed Rd.,Drayton Valley,21833 Humphrey, Briar W.,1-583-466-4027,Morbi.accumsan.laoreet@Loremipsumdolor.net,Ap #642-6497 Id Rd.,Lochgilphead,16394 Benson, Tasha H.,1-898-918-7872,consequat@enimEtiam.ca,P.O. 197 号信箱，4720 Ipsum。圣，德福，56688 Emerson, Susan P.,1-190-818-1919,dignissim@liberoatauctor.ca,P.O. Box 482, 7813 多洛尔。大道，圣安东尼奥，M8C 7F6 Dunn, Alexander U.,1-222-379-2231,libero.Donec.consectetuer@nonegestasa.ca,803-958 Lectus Rd.,Raleigh,74078

Answer 1

假设我们将整个文件读入内存，我将通过以下方式实现模型（QAbstractTableModel 的子类）：

CustomAbstractModel::CustomAbstractModel(const QString &filePath,
                                         QObject *parent)
    :
        QAbstractTableModel(parent)
{
    // Parse the file and store its data in an internal data structure
    QFile file(filePath);
    if (file.open(QIODevice::ReadOnly))
    {
        QTextStream in(&file);
        while (!in.atEnd())
        {
            // Assuming that m_data is a std::vector<QString>
            m_data.emplace_back(in.readLine());
        }
    }    
}

QVariant CustomAbstractModel::headerData(int section,
                                         Qt::Orientation orientation,
                                         int role) const
{
    if (orientation == Qt::Horizontal && role == Qt::DisplayRole &&
        !m_data.empty())
    {
        // Read the column names from the first line        
        const QString &firstLine = m_data.front();
        QStringList headers = firstLine.split(',');
        return headers.at(section);
    }    
}

int CustomAbstractModel::rowCount(const QModelIndex &parent) const
{
    if (!m_data.empty())
    {
        return m_data.size() - 1; // First line is the column names data
    }
    return 0;
}

int CustomAbstractModel::columnCount(const QModelIndex &parent) const
{
    if(!m_data.empty())
    {
        const QString &firstLine = m_data.front();
        return firstLine.count(",") + 1;
    }
    return 0;    
}

QVariant CustomAbstractModel::data(const QModelIndex &index, int role) const
{
    if (m_data.empty() && role == Qt::DisplayRole)
    {
        // First line is the header data.
        const QString &line = m_data[index.row() + 1];
        QStringList columnData = firstLine.split(',');
        return columnData.at(index.column());
    }
    return QVariant();    
}