class TreeWidget(QTreeWidget):
customMimeType = "application/x-customTreeWidgetdata"
def mimeTypes(self):
mimetypes = QTreeWidget.mimeTypes(self)
mimetypes.append(TreeWidget.customMimeType)
return mimetypes
def startDrag(self, supportedActions):
drag = QDrag(self)
mimedata = self.model().mimeData(self.selectedIndexes())
encoded = QByteArray()
stream = QDataStream(encoded, QIODevice.WriteOnly)
self.encodeData(self.selectedItems(), stream)
mimedata.setData(TreeWidget.customMimeType, encoded)
drag.setMimeData(mimedata)
drag.exec_(supportedActions)
def dropEvent(self, event):
if event.source() == self:
event.setDropAction(Qt.MoveAction)
QTreeWidget.dropEvent(self, event)
elif isinstance(event.source(), QTreeWidget):
if event.mimeData().hasFormat(TreeWidget.customMimeType):
encoded = event.mimeData().data(TreeWidget.customMimeType)
parent = self.itemAt(event.pos())
items = self.decodeData(encoded, event.source())
for it in items:
item = QTreeWidgetItem(parent)
self.fillItem(it, item)
self.fillItems(it, item)
event.acceptProposedAction()
def fillItem(self, inItem, outItem):
for col in range(inItem.columnCount()):
for key in range(Qt.UserRole):
role = Qt.ItemDataRole(key)
outItem.setData(col, role, inItem.data(col, role))
def fillItems(self, itFrom, itTo):
for ix in range(itFrom.childCount()):
it = QTreeWidgetItem(itTo)
ch = itFrom.child(ix)
self.fillItem(ch, it)
self.fillItems(ch, it)
def encodeData(self, items, stream):
stream.writeInt32(len(items))
for item in items:
p = item
rows = []
while p is not None:
rows.append(self.indexFromItem(p).row())
p = p.parent()
stream.writeInt32(len(rows))
for row in reversed(rows):
stream.writeInt32(row)
return stream
def decodeData(self, encoded, tree):
items = []
rows = []
stream = QDataStream(encoded, QIODevice.ReadOnly)
while not stream.atEnd():
nItems = stream.readInt32()
for i in range(nItems):
path = stream.readInt32()
row = []
for j in range(path):
row.append(stream.readInt32())
rows.append(row)
for row in rows:
it = tree.topLevelItem(row[0])
for ix in row[1:]:
it = it.child(ix)
items.append(it)
return items
为了执行此任务,我们必须区分该操作是来自他自己还是来自另一个小部件,因为它被
dropEvent
方法覆盖,这将返回一个QDropEvent
类型的事件,该事件具有返回执行该操作的对象的方法source()
:每个
^{pr2}$QTreeWidgetItem
都与其父对象相关联,因此如果它移动到父对象,子对象也将移动。在这是最复杂的任务,因为当
QTreeWidget
使用拖放时,它使用mimetypex-qabstractitemmodeldatalist
来存储与项的QModelIndex相关联的行和列的信息,以及一个包含角色及其值的字典:所以知道行和列是不可能的,因为你必须有父项,所以也不可能得到你的子项。因此,您应该寻找另一种策略,解决方案是创建一个新的mimetype,在其中保存必要的信息以再次获取该项,唯一的方法是保存该项的行,然后保存父项的行,然后再保存父项的父项行,直到到达某个
topLevelItem
。在因为你已经有了这个项目,你可以访问你的孩子和他们所包含的信息。完整实现如下:
在下面的link中,您将看到一个示例
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