QTreeWidget通过拖动重新排序子项 [英] QTreeWidget reordering child items by dragging
问题描述
我有一个QTreeWidget显示单个根节点和一级子节点。
我需要允许子节点的重新排序。
它们不能重新生成。
这是我如何在QTreeWidget中启用项目的拖动:
ui-> levelElements-> setSelectionMode(QAbstractItemView :: SingleSelection);
ui-> levelElements-> setDragEnabled(true);
ui-> levelElements-> viewport() - > setAcceptDrops(true);
ui-> levelElements-> setDropIndicatorShown(true);
ui-> levelElements-> setDragDropMode(QAbstractItemView :: InternalMove);
根项目插入如下:
pItem = new QTreeWidgetItem(ui-> levelElements);
pItem-> setText(0,node.firstChild()。nodeValue());
pItem-> setFlags(Qt :: ItemIsEnabled | Qt :: ItemIsSelectable | Qt :: ItemIsDropEnabled);
当我插入一个子视图时,它被声明为这样:
pItem = new QTreeWidgetItem();
pItem-> setText(0,strFileName);
pItem-> setFlags(Qt :: ItemIsEnabled | Qt :: ItemIsSelectable | Qt :: ItemIsDragEnabled);
pTreeRoot-> addChild(pItem);
此时,我可以拖动一个子项目,然后重新插入子项目列表。我也可以将它移动到根级别 - 我不想要的。
我使用QT Creator v3,所以QTreeWidget是在我的UI定义文件。
例如,您可以覆盖:p>
< virtual void dropEvent(QDropEvent * event)
#include< QApplication>
#include< QTreeWidget>
#include< QTreeWidgetItem>
#include< QDropEvent>
类TreeView:public QTreeWidget
{
public:
TreeView()
{
resize(200,300);
setSelectionMode(QAbstractItemView :: SingleSelection);
setDragEnabled(true);
viewport() - > setAcceptDrops(true);
setDropIndicatorShown(true);
setDragDropMode(QAbstractItemView :: InternalMove);
QTreeWidgetItem * parentItem = new QTreeWidgetItem(this);
parentItem - > setText(0,Test);
parentItem-> setFlags(Qt :: ItemIsEnabled | Qt :: ItemIsSelectable | Qt :: ItemIsDropEnabled);
for(int i = 0; i <10; ++ i)
{
QTreeWidgetItem * pItem = new QTreeWidgetItem(parentItem);
pItem-> setText(0,QString(Number%1)。arg(i));
pItem-> setFlags(Qt :: ItemIsEnabled | Qt :: ItemIsSelectable | Qt :: ItemIsDragEnabled);
pItem-> addChild(pItem);
}
}
private:
virtual void dropEvent(QDropEvent * event)
{
QModelIndex droppedIndex = indexAt(event-> pos());
if(!droppedIndex.isValid())
return;
QTreeWidget :: dropEvent(event);
}
};
int main(int argc,char * argv [])
{
QApplication a(argc,argv);
TreeView widget;
widget.show();
return a.exec();
}
I have a QTreeWidget which displays a single root node and one level of child nodes only. I need to permit the re-ordering of the child nodes. They must never be re-parented.
This is how I enable the dragging of items in the QTreeWidget :
ui->levelElements->setSelectionMode(QAbstractItemView::SingleSelection);
ui->levelElements->setDragEnabled(true);
ui->levelElements->viewport()->setAcceptDrops(true);
ui->levelElements->setDropIndicatorShown(true);
ui->levelElements->setDragDropMode(QAbstractItemView::InternalMove);
The root item is inserted like this :
pItem = new QTreeWidgetItem(ui->levelElements);
pItem->setText(0, node.firstChild().nodeValue());
pItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDropEnabled);
When I insert a child into the view, it is declared like this :
pItem = new QTreeWidgetItem();
pItem->setText(0, strFileName);
pItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled);
pTreeRoot->addChild(pItem);
At this point, I am able to drag a child item and "re-insert" it in the list of child items. I can also move it to the root level - which I do not want.
I am using QT Creator v3 and so the QTreeWidget is within my UI definition file.
Have I missed something here ?
For example you can override: virtual void dropEvent(QDropEvent * event)
#include <QApplication>
#include <QTreeWidget>
#include <QTreeWidgetItem>
#include <QDropEvent>
class TreeView: public QTreeWidget
{
public:
TreeView()
{
resize(200, 300);
setSelectionMode(QAbstractItemView::SingleSelection);
setDragEnabled(true);
viewport()->setAcceptDrops(true);
setDropIndicatorShown(true);
setDragDropMode(QAbstractItemView::InternalMove);
QTreeWidgetItem* parentItem = new QTreeWidgetItem(this);
parentItem->setText(0, "Test");
parentItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDropEnabled);
for(int i = 0; i < 10; ++i)
{
QTreeWidgetItem* pItem = new QTreeWidgetItem(parentItem);
pItem->setText(0, QString("Number %1").arg(i) );
pItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled);
pItem->addChild(pItem);
}
}
private:
virtual void dropEvent(QDropEvent * event)
{
QModelIndex droppedIndex = indexAt( event->pos() );
if( !droppedIndex.isValid() )
return;
QTreeWidget::dropEvent(event);
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
TreeView widget;
widget.show();
return a.exec();
}
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