Question

我有一个自定义的QTreeWidget类，其中覆盖了dropEvent()方法。这是方法：

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

    if (!droppedIndex.isValid())
        return;

    // other logic

    QTreeWidget::dropEvent(event);
}

如何确定项目是否会插入项目的上方，内部或下方？

Answer 1

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

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
    }
}

获取相对于QTreeWidget

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