获取相对于 QTreeWidget 上项目的放置位置

Question

我有一个自定义 QTreeWidget 类，其中 dropEvent() 方法被覆盖。 方法如下：

void QCustomTreeWidget::dropEvent(QDropEvent * event)
{
    QModelIndex droppedIndex = indexAt(event->pos());

    if (!droppedIndex.isValid())
        return;

    // other logic

    QTreeWidget::dropEvent(event);
}

我如何确定该项目将插入它被丢弃的项目的上方、内部还是下方？

Answer 1

您需要使用DropIndicatorPosition。使用switch 语句，您可以轻松实现您想要的。

bool bAbove = false; // boolean for the case when you are above an item

QModelIndex dropIndex = indexAt(event->pos());
DropIndicatorPosition dropIndicator = dropIndicatorPosition();

if (!dropIndex.parent().isValid() && dropIndex.row() != -1)
{
    switch (dropIndicator)
    {
    case QAbstractItemView::AboveItem:
        // manage a boolean for the case when you are above an item
        bAbove = true;
        break;
    case QAbstractItemView::BelowItem:
        // something when being below an item
        break;
    case QAbstractItemView::OnItem:
        // you're on an item, maybe add the current one as a child
        break;
    case QAbstractItemView::OnViewport:
        // you are not on your tree
        break;
    }

    if(bAbove) // you are above an item
    {
        // manage this case
    }
}