DiagramDesigner/source/topologyTree.cpp

#include <QMouseEvent>
#include <QMimeData>
#include <QDrag>
#include <QPainter>
#include "topologyTree.h"
#include "global.h"

TopologyTree::TopologyTree(QWidget *parent)
    : QTreeView(parent)
{

}

TopologyTree::~TopologyTree()
{

}

void TopologyTree::mouseMoveEvent(QMouseEvent *event)
{
    if (event->buttons() & Qt::LeftButton) {
        QModelIndex index = indexAt(event->pos());
        if (index.isValid()) {
            // 创建QMimeData，并将选中项的文本放入
            QMimeData *mimeData = new QMimeData();
            mimeData->setText(model()->data(index, Qt::DisplayRole).toString());
            QString id = index.data(Qt::UserRole).toString();
            mimeData->setData("application/id",id.toLocal8Bit());

            // 创建拖拽对象
            QDrag *drag = new QDrag(this);
            drag->setMimeData(mimeData);

            // 设置拖拽的图标（这里用一个简单的图标，也可以使用其他方式）
            QPixmap pixmap(100, 30);
            pixmap.fill(Qt::white);
            QPainter painter(&pixmap);
            painter.drawText(0, 20, model()->data(index, Qt::DisplayRole).toString());
            drag->setPixmap(pixmap);
            drag->setHotSpot(event->pos() - rect().topLeft());

            // 启动拖拽操作
            drag->exec(Qt::CopyAction);
        }
    }
}