Qt 两个重载QListWidget控件对象实现selectitem drag拖拽

#include <QListWidget>
#include <QWidget>
#include <QMimeData>
#include <QDrag>
#include <QMouseEvent>
#include <QDragEnterEvent>
#include <qDebug>
#include <QApplication>

class myListWidget : public QListWidget
{
    Q_OBJECT
public:
    explicit myListWidget(QWidget *parent = nullptr);

protected:
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void dragEnterEvent(QDragEnterEvent *event);
    void dragMoveEvent(QDragMoveEvent *event);
    void dropEvent(QDropEvent *event);
    void InitMyListWidget();

private:
    QListWidgetItem * current_item;
    QPoint start;
};









myListWidget::myListWidget(QWidget *parent) : QListWidget(parent)
{
    this->setAcceptDrops(true);
    current_item = NULL;
}

void myListWidget::mousePressEvent(QMouseEvent *event)
{
    qDebug()<<"mousePressEvent";
    if(event->button() != Qt::LeftButton){//按下的不是鼠标左键
        return;
    }
    start = event->pos();
    QListWidget::mousePressEvent(event);
}


void myListWidget::mouseMoveEvent(QMouseEvent *event)
{
    qDebug()<<"mouseMoveEvent";
    if(event->buttons() & Qt::LeftButton){//按下的是鼠标左键
        //判断拖动的长度大于起始长度才认为是拖动,否则不做拖动
        int distance = (event->pos() - start).manhattanLength();
        if(distance >= QApplication::startDragDistance()){


            //获取当前被选中的值
            current_item = this->currentItem();
            if(current_item){
                //准备需要传送的数据
                QMimeData * mimedata = new QMimeData();
                mimedata->setText(current_item->text());
                //test = current_item->text();
                //准备传送的对象
                QDrag* drag = new QDrag(this);
                drag->setMimeData(mimedata);

                //1.1 设置drag对象的图标,拖拽时显示的图标
                drag->setPixmap(QPixmap(":/new/prefix1/stop.png"));
                //1.2进行拖动操作
                if(Qt::MoveAction == drag->exec(Qt::MoveAction)){
                    delete current_item;
                }


                QListWidget::mouseMoveEvent(event);
            }
        }
    }
}

void myListWidget::dragEnterEvent(QDragEnterEvent *event)
{
    qDebug()<<"dragEnterEvent";
    QListWidget* source  = qobject_cast<QListWidget*>(event->source());
    //判断是否位空,判断自己是为自己
    if(source!=NULL && (source!=this)){
        event->setDropAction(Qt::MoveAction);
        event->accept();
    }
}

void myListWidget::dragMoveEvent(QDragMoveEvent *event)
{
    qDebug()<<"dragMoveEvent";
    QListWidget* source  = qobject_cast<QListWidget*>(event->source());
    //判断是否位空,判断自己是为自己
    if(source!=NULL && (source!=this)){
        event->setDropAction(Qt::MoveAction);
        event->accept();
    }
}

void myListWidget::dropEvent(QDropEvent *event)
{
    QListWidget* source = qobject_cast<QListWidget*>(event->source());
    //判断是否为空,判断是否自身为空
    if(source != NULL && source != this){
        QList<QListWidgetItem*>  it = source->selectedItems();
        //QString str = event->mimeData()->text();
        //QListWidgetItem * l1 = new QListWidgetItem(QIcon(":/new/prefix1/video-ok.png"),str);
        QListWidgetItem * l1 = new QListWidgetItem(*it.front());//
        this->addItem(l1);
        this->setCurrentItem(l1);
        event->setDropAction(Qt::MoveAction);
        event->accept();

    }
}