PyQt5 可拖动图标从列表视图到另一个

Question

我很难将图标从列表视图（ViewMode 设置为 IconMode）拖放到另一个。它类似于我在docs 中找到的内容。

场景：用户将 QIcon 1 从 ListView 1 拖放到 ListView 2。ListView 2 应将 QIcon 1 添加到其模型中。此外，当将 特定 QIcon 添加到 ListView 2 时，我想做一些后台工作。我如何知道 QIcon 1 被删除到 ListView 2 而不是 QIcon 2？

主窗口（设置布局，将图像加载到列表视图 1）：

class Ui_MainWindow(object):
...
    def loadImages(self):
        model = QStandardItemModel()
        images = Path("images").glob("*.*")
        for image in images:
            item = QStandardItem()
            item.setIcon(QIcon(str(image)))
            model.appendRow(item)

        self.listView1.setModel(model)

列表视图 1：

class ListView1(QListView):
    def __init__(self):
        super().__init__()
        self.setAcceptDrops(False)
        self.setViewMode(QtWidgets.QListView.IconMode)
        self.setEditTriggers(QAbstractItemView.NoEditTriggers)
        self.setIconSize(QSize(50, 50))
        self.setResizeMode(QtWidgets.QListView.Adjust)
        self.setDragDropMode(QAbstractItemView.DragOnly)

列表视图 2：

class ListView2(QListView):
    def __init__(self):
        super().__init__()
        self.setViewMode(QtWidgets.QListView.IconMode)
        self.setDragDropMode(QAbstractItemView.DropOnly)
        self.setIconSize(QSize(50, 50))
        self.setAcceptDrops(True)

    def dragEnterEvent(self, event):
        event.accept()

    def dragMoveEvent(self, event):
        event.accept()

    def dropEvent(self, event):
        event.accept()
        event.setDropAction(QtCore.Qt.MoveAction)
        event.acceptProposedAction()

如何将图标从列表视图 1 拖放到列表视图 2 并访问其属性？

Answer 1

没有必要覆盖dragEnterEvent、dragMoveEvent 或dropEvent，因为这些实现已经存在并且可以正常工作，您指出的示例是针对没有实现这些事件的其他类型的小部件。

from pathlib import Path
from PyQt5 import QtCore, QtGui, QtWidgets

class LListView(QtWidgets.QListView):
    def __init__(self, parent=None):
        super(LListView, self).__init__(parent)
        self.model = QtGui.QStandardItemModel(self)
        self.setModel(self.model)

        self.setAcceptDrops(False)
        self.setViewMode(QtWidgets.QListView.IconMode)
        self.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.setIconSize(QtCore.QSize(50, 50))
        self.setResizeMode(QtWidgets.QListView.Adjust)
        self.setDragDropMode(QtWidgets.QAbstractItemView.DragOnly)

class RListView(QtWidgets.QListView):
    def __init__(self, parent=None):
        super(RListView, self).__init__(parent)
        self.model = QtGui.QStandardItemModel(self)
        self.setModel(self.model)

        self.setAcceptDrops(True)
        self.setViewMode(QtWidgets.QListView.IconMode)
        self.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.setIconSize(QtCore.QSize(50, 50))
        self.setResizeMode(QtWidgets.QListView.Adjust)
        self.setDragDropMode(QtWidgets.QAbstractItemView.DropOnly)


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        central_widget = QtWidgets.QWidget()
        self.l_view = LListView()
        self.r_view = RListView()

        self.setCentralWidget(central_widget)
        lay = QtWidgets.QHBoxLayout(central_widget)
        lay.addWidget(self.l_view)
        lay.addWidget(self.r_view)
        self.loadImages()

    def loadImages(self):
        images = Path("images").glob("*.*")
        for image in images:
            item = QtGui.QStandardItem()
            item.setIcon(QtGui.QIcon(str(image)))
            self.l_view.model.appendRow(item)


if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

更新：

如果要添加标识符，可以通过创建项目时传递的角色来完成，然后在dropEvent() 中获取所有角色，然后获取所需的角色并通过它获得标识符：

from pathlib import Path
from PyQt5 import QtCore, QtGui, QtWidgets

class LListView(QtWidgets.QListView):
    def __init__(self, parent=None):
        super(LListView, self).__init__(parent)
        self.m_model = QtGui.QStandardItemModel(self)
        self.setModel(self.m_model)

        self.setAcceptDrops(False)
        self.setViewMode(QtWidgets.QListView.IconMode)
        self.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.setIconSize(QtCore.QSize(50, 50))
        self.setResizeMode(QtWidgets.QListView.Adjust)
        self.setDragDropMode(QtWidgets.QAbstractItemView.DragOnly)

class RListView(QtWidgets.QListView):
    def __init__(self, parent=None):
        super(RListView, self).__init__(parent)
        self.m_model = QtGui.QStandardItemModel(self)
        self.setModel(self.m_model)

        self.setAcceptDrops(True)
        self.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.setIconSize(QtCore.QSize(50, 50))
        self.setResizeMode(QtWidgets.QListView.Adjust)
        self.setDragDropMode(QtWidgets.QAbstractItemView.DropOnly)

    def dropEvent(self, event):
        last_row_count = self.model().rowCount()
        super(RListView, self).dropEvent(event)
        # check if an item is added
        if self.model().rowCount() > last_row_count:
            md = event.mimeData()
            fmt = "application/x-qabstractitemmodeldatalist"
            if md.hasFormat(fmt):
                encoded = md.data(fmt)
                stream = QtCore.QDataStream(encoded, QtCore.QIODevice.ReadOnly)
                datas = []
                item = {}
                while not stream.atEnd():
                    row = stream.readInt32()
                    column = stream.readInt32()
                    map_items = stream.readInt32()
                    for i in range(map_items):
                        key = stream.readInt32()
                        value = QtCore.QVariant()
                        stream >> value
                        item[QtCore.Qt.ItemDataRole(key)] = value
                    datas.append(item)
                for data in datas:
                    identifier = data[QtCore.Qt.UserRole+1].value()
                    print("identifier: ", identifier)


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        central_widget = QtWidgets.QWidget()
        self.l_view = LListView()
        self.r_view = RListView()

        self.setCentralWidget(central_widget)
        lay = QtWidgets.QHBoxLayout(central_widget)
        lay.addWidget(self.l_view)
        lay.addWidget(self.r_view)
        self.loadImages()

    def loadImages(self):
        images = Path("images").glob("*.*")
        for i, image in enumerate(images):
            item = QtGui.QStandardItem()
            identifier = "img_{:06d}".format(i+1)
            item.setData(identifier, QtCore.Qt.UserRole+1)
            item.setIcon(QtGui.QIcon(str(image)))
            self.l_view.m_model.appendRow(item)


if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())