在qml的listview中如何使用QAbstractItemModel

在QML中使用QAbstractItemModel需要通过C++代码编写自定义的QAbstractItemModel子类。下面是一个简单的示例：

1. 编写自定义的QAbstractItemModel子类

// mymodel.h
#ifndef MYMODEL_H
#define MYMODEL_H

#include <QAbstractItemModel>

class MyModel : public QAbstractItemModel
{
    Q_OBJECT

public:
    explicit MyModel(QObject *parent = nullptr);

    // 获取模型数据的数量和索引
    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
    int columnCount(const QModelIndex &parent = QModelIndex()) const override;
    QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;

    // 获取模型数据
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;

private:
    QStringList m_data;
};

#endif // MYMODEL_H

// mymodel.cpp
#include "mymodel.h"

MyModel::MyModel(QObject *parent)
    : QAbstractItemModel(parent)
{
    // 初始化模型数据
    m_data << "Item 1" << "Item 2" << "Item 3";
}

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

    return m_data.count();
}

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

    return 1;
}

QModelIndex MyModel::index(int row, int column, const QModelIndex &parent) const
{
    if (parent.isValid() || row < 0 || row >= m_data.count() || column < 0 || column >= 1)
        return QModelIndex();

    return createIndex(row, column);
}

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

    if (role == Qt::DisplayRole || role == Qt::EditRole)
        return m_data.at(index.row());

    return QVariant();
}

2. 在QML中使用自定义的QAbstractItemModel子类

// main.qml
import QtQuick 2.0
import QtQuick.Controls 2.0

ApplicationWindow {
    visible: true
    width: 400
    height: 400

    // 创建自定义模型
    MyModel {
        id: myModel
    }

    // 使用ListView显示模型数据
    ListView {
        anchors.fill: parent
        model: myModel
        delegate: Text {
            text: model.display
        }
    }
}