QML ListView performance issues with large data sets in Qt 6.2
I'm reviewing some code and I'm working on a personal project and I'm currently experiencing performance issues when rendering a large data set in a QML ListView using Qt 6.2. My model has around 10,000 items, and while the ListView displays them, the scrolling is noticeably laggy and unresponsive. I've implemented a simple model using QAbstractListModel, and I suspect the performance hit may come from the way I'm handling the data. Here's a simplified version of my ListView and model implementation: ```cpp // MyModel.h class MyModel : public QAbstractListModel { Q_OBJECT public: MyModel(QObject *parent = nullptr) : QAbstractListModel(parent) { // Populate model with data for (int i = 0; i < 10000; ++i) { items.append(QString("Item %1").arg(i)); } } int rowCount(const QModelIndex &parent = QModelIndex()) const override { return items.size(); } QVariant data(const QModelIndex &index, int role) const override { if (role == Qt::DisplayRole) { return items.at(index.row()); } return QVariant(); } private: QStringList items; }; ``` And in QML, I have: ```qml ListView { width: 400; height: 300; model: myModel delegate: Item { width: ListView.view.width; height: 50; Text { text: model.display } } } ``` I've noticed that as I scroll through the ListView, it stutters significantly. I read about using `ListView` with a `ListModel` and possibly enabling `cacheBuffer` to improve performance, but I haven't seen any improvement. Also, I considered switching to a `GridView`, but since my data is linear and I need the vertical scrolling, Iād prefer to stick with `ListView`. I've tried profiling the application using Qt's built-in tools, and it shows that the rendering time spikes during scrolling. Is there a best practice or optimization that I might have overlooked to handle large data sets in QML effectively? Any insights would be greatly appreciated! This is part of a larger application I'm building. What am I doing wrong? The stack includes Cpp and several other technologies. Hoping someone can shed some light on this.