Question

我有一个QListWidget和一个QTreeWidget，我希望能够在每个内部以及它们之间拖动一个或多个列表项。我有内部拖放功能，但不确定如何在它们之间拖动。

当我在下面的代码中打印event.mimeData().formats()时，上面写着['application/x-qabstractitemmodeldatalist']。我被困在如何提取该项目的文本和索引（它应该是QListWidgetItem或QTreeWidgetItem，对吗？）上，所以我可以从源窗口小部件中删除原始项目并将新项目添加到目标窗口小部件中，我该怎么办那？

我尝试使用此处的代码：
https://wiki.python.org/moin/PyQt/Handling%20Qt%27s%20internal%20item%20MIME%20type

因此，当我在小部件之间拖动项目时，我的代码获得了QVariant项目，但是我仍然不知道该如何处理以获取项目文本和索引。

from PyQt5 import QtCore, QtWidgets, QtGui
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QTreeWidgetItem
import sys

class Tree(QtWidgets.QTreeWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.setDragDropMode(self.DragDrop)
        self.setSelectionMode(self.ExtendedSelection)
        self.setAcceptDrops(True)

        for text in ['tree1','tree2','tree3']:
            treeItem = QtWidgets.QTreeWidgetItem(self, [text])
            treeItem.setFlags(treeItem.flags() & ~QtCore.Qt.ItemIsDropEnabled)
            self.addTopLevelItem(treeItem)

    def dropEvent(self, event):
        if event.source() == self:
            event.setDropAction(Qt.MoveAction)
            QtWidgets.QTreeWidget.dropEvent(self, event)
        else:
            bytearray = event.mimeData().data('application/x-qabstractitemmodeldatalist')
            data_items = decode_data(bytearray)

            for item in data_items:
                print(item)
                # What do I do with this?


class List(QtWidgets.QListWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.setDragDropMode(self.DragDrop)
        self.setSelectionMode(self.ExtendedSelection)
        self.setAcceptDrops(True)

        for text in ['list1','list2','list3']:
            self.addItem(text)

    def dropEvent(self, event):
        if event.source() == self:
            event.setDropAction(Qt.MoveAction)
            QtWidgets.QListWidget.dropEvent(self, event)
        else:
            bytearray = event.mimeData().data('application/x-qabstractitemmodeldatalist')
            data_items = decode_data(bytearray)

            for item in data_items:
                print(item)
                # What do I do with this?


def decode_data(bytearray):

    data = []
    item = {}

    ds = QtCore.QDataStream(bytearray)
    while not ds.atEnd():

        row = ds.readInt32()
        column = ds.readInt32()

        map_items = ds.readInt32()
        for i in range(map_items):
            key = ds.readInt32()

            value = QtCore.QVariant()
            ds >> value
            item[Qt.ItemDataRole(key)] = value

        data.append(item)
    return data

if __name__=='__main__':

    app = QtWidgets.QApplication(sys.argv)

    layout = QtWidgets.QHBoxLayout()
    layout.addWidget(Tree())
    layout.addWidget(List())

    container = QtWidgets.QWidget()
    container.setLayout(layout)
    container.show()

    app.exec_()

Answer 1

您必须使用decode_data返回的信息创建项目，这些信息是所拖动的每个项目的角色和值：

class Tree(QtWidgets.QTreeWidget):
    # ...

    def dropEvent(self, event):
        if event.source() == self:
            event.setDropAction(QtCore.Qt.MoveAction)
            super().dropEvent(event)
        elif isinstance(event.source(), QtWidgets.QListWidget):
            item = self.itemAt(event.pos())
            ix = self.indexAt(event.pos())
            col = 0 if item is None else ix.column()
            item = self.invisibleRootItem() if item is None else item            
            ba = event.mimeData().data('application/x-qabstractitemmodeldatalist')
            data_items = decode_data(ba)
            for data_item in data_items:
                it = QtWidgets.QTreeWidgetItem()
                item.addChild(it)
                for data in data_items:
                    for r, v in data.items():
                        it.setData(col, r, v)

class List(QtWidgets.QListWidget):
    # ... 

    def dropEvent(self, event):
        if event.source() == self:
            event.setDropAction(QtCore.Qt.MoveAction)
            QtWidgets.QListWidget.dropEvent(self, event)
        elif isinstance(event.source(), QtWidgets.QTreeWidget):
            item = self.itemAt(event.pos())
            row = self.row(item) if item else self.count()
            ba = event.mimeData().data('application/x-qabstractitemmodeldatalist')
            data_items = decode_data(ba)
            for i, data_item in enumerate(data_items):
                it = QtWidgets.QListWidgetItem()
                self.insertItem(row+i, it)
                for r, v in data_item.items():
                    it.setData(r,v)

在PyQt5中的QTreeWidget和QListWidget之间拖动项目？

1 个答案: