PyQt：Drag＆amp;在应用程序外部删除Pixmap不适用于子窗口小部件

Question

我想使用图标来表示我的项目，同时将其拖到应用程序之外（如桌面）。只要我在父级别上使用小部件，它就可以正常工作。

工作示例：

modern.cast(my.df, .(x.2012, y.2012) ~ .(x.2013, y.2013), fun)

但是当我想在我的子窗口小部件中实现这个功能时，它只在应用程序内部工作：

import sys
from PyQt4 import QtGui, QtCore

class Button(QtGui.QPushButton):
    def mouseMoveEvent(self, e):
        if e.buttons() != QtCore.Qt.LeftButton:
            return
        mimeData = QtCore.QMimeData()
        mimeData.setText('%d,%d' % (e.x(), e.y()))

        pixmap = QtGui.QPixmap.grabWidget(self)

        drag = QtGui.QDrag(self)
        drag.setMimeData(mimeData)
        drag.setPixmap(pixmap)
        drag.setHotSpot(e.pos())

        if drag.exec_(QtCore.Qt.CopyAction | QtCore.Qt.MoveAction) == QtCore.Qt.MoveAction:
            print 'moved'
        else:
            print 'copied'

    def mousePressEvent(self, e):
        QtGui.QPushButton.mousePressEvent(self, e)
        if e.button() == QtCore.Qt.LeftButton:
            print 'press'

class Example(QtGui.QWidget):
    def __init__(self):
        super(Example, self).__init__()
        self.setAcceptDrops(True)

        button = Button('Button', self)
        button.move(100, 65)

        self.buttons = [button]

        self.setWindowTitle('Copy or Move')
        self.setGeometry(300, 300, 280, 150)

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    ex.show()
    app.exec_()  

我怎样才能在第二个例子中使用它？ 当我在不同的其他小部件中实现自定义class Item(QtGui.QListWidgetItem): def __init__(self, parent=None): super(Item, self).__init__(parent=parent) def mouseMoveEvent(self, e): if e.buttons() != QtCore.Qt.LeftButton: return mimeData = QtCore.QMimeData() mimeData.setText('%d,%d' % (e.x(), e.y())) pixmap = QtGui.QPixmap.grabWidget(self) drag = QtGui.QDrag(self) drag.setMimeData(mimeData) drag.setPixmap(pixmap) drag.setHotSpot(e.pos()) if drag.exec_(QtCore.Qt.CopyAction | QtCore.Qt.MoveAction) == QtCore.Qt.MoveAction: print 'moved' else: print 'copied' def mousePressEvent(self, e): QtGui.QListWidget.mousePressEvent(self, e) if e.button() == QtCore.Qt.LeftButton: print 'press' class ListWidget(QtGui.QListWidget): def __init__(self, parent=None): super(ListWidget, self).__init__(parent=parent) self.setMovement(QtGui.QListView.Static) self.setViewMode(QtGui.QListView.IconMode) self.setResizeMode(QtGui.QListView.Adjust) self.setWrapping(True) self.setSpacing(5) self.setDragEnabled(True) self.setAcceptDrops(True) for name in ["Item_01","Item_02", 'Item_03', 'Item_04']: item = Item() item.setText(name) self.addItem(item) if __name__ == '__main__': app = QtGui.QApplication(sys.argv) win = ListWidget() win.show() sys.exit(app.exec_()) 时，它也应该有用。

由于