QTreeView实现节点拖动.zip

#include "TreeModel.h" #include <QDebug> #include <qmimedata.h> #include <qdatastream.h> TreeModel::TreeModel(QObject *parent) : QAbstractItemModel(parent) { m_pRootItem = new TreeItem(QString("root"), nullptr); } TreeModel::~TreeModel() { } void TreeModel::createdata() { for (int i = 0; i < 10; i++) { beginInsertRows(QModelIndex(), i, i); TreeItem* item = new TreeItem(QString::number(i), m_pRootItem); endInsertRows(); } } void TreeModel::DeleteData() { for (int i = 9; i >= 0; i--) { beginRemoveRows(QModelIndex(), i, i); m_pRootItem->RemoveItem(i); endRemoveRows(); } } QModelIndex TreeModel::index(int row, int column, const QModelIndex & parent) const { if (!hasIndex(row, column, parent)) return QModelIndex(); TreeItem* parentItem = 0; if (!parent.isValid()) parentItem = m_pRootItem; else parentItem = static_cast<TreeItem*>(parent.internalPointer()); TreeItem* item = parentItem->Child(row); if (item == nullptr) return QModelIndex(); return createIndex(row, column, item); } QModelIndex TreeModel::parent(const QModelIndex & child) const { if (!child.isValid()) return QModelIndex(); TreeItem* item = static_cast<TreeItem*>(child.internalPointer()); if (item->ParentItem() == nullptr) return QModelIndex(); if (item->ParentItem() == m_pRootItem) return createIndex(0,0,m_pRootItem); return createIndex(item->ParentItem()->row(),0,item->ParentItem()); } int TreeModel::rowCount(const QModelIndex & parent) const { if (!parent.isValid()) { return m_pRootItem->childRows(); } TreeItem* item = static_cast<TreeItem*>(parent.internalPointer()); return item->childRows(); } int TreeModel::columnCount(const QModelIndex & parent) const { Q_UNUSED(parent); return 1; } QVariant TreeModel::data(const QModelIndex & index, int role) const { if(!index.isValid()) return QVariant(); if (role == Qt::DisplayRole) return static_cast<TreeItem*>(index.internalPointer())->data(role); return QVariant(); } bool TreeModel::dropMimeData(const QMimeData * data, Qt::DropAction action, int row, int column, const QModelIndex & parent) { QByteArray array = data->data(QString("hehe")); QDataStream stream(&array, QIODevice::ReadOnly); qint64 p; stream >> p; QModelIndex* index = (QModelIndex*)p; TreeItem* item = static_cast<TreeItem*>(index->internalPointer()); TreeItem* ParentItem = static_cast<TreeItem*>(parent.internalPointer()); beginMoveRows(index->parent(), index->row(), index->row(), parent, ParentItem->childRows()); item->ParentItem()->RemoveItem(item->row()); ParentItem->AddChild(item); endMoveRows(); delete index; return false; } Qt::DropActions TreeModel::supportedDropActions() const { return Qt::MoveAction; } QMimeData * TreeModel::mimeData(const QModelIndexList & indexes) const { QMimeData* mimeData = QAbstractItemModel::mimeData(indexes); //只取第一个 for (int i = 0; i < indexes.count(); i++) { QModelIndex index = indexes[i]; QModelIndex* p = new QModelIndex(index); TreeItem* item = static_cast<TreeItem*>(index.internalPointer()); qDebug() << item->data(Qt::DisplayRole).toString(); QByteArray array; QDataStream stream(&array, QIODevice::WriteOnly); stream << (qint64)p; mimeData->setData(QString("hehe"), array); return mimeData; } return mimeData; } Qt::ItemFlags TreeModel::flags(const QModelIndex & index) const { if(index.isValid()) return QAbstractItemModel::flags(index) | Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled; else return QAbstractItemModel::flags(index) | Qt::ItemIsDropEnabled; }