本文分成兩部分，第一部分通過python3+PyQt5實現自定義數據的拖放操作。第二部分則對第一部分的程序進行修改，增加拖放操作時，菜單提示是否移動或拷貝，還有可以通過ctrl鍵盤來設置移動過程中拷貝源而非會將源刪除。

自定義數據MIME數據類型QMimeData，MIME是一種用于處理具有多個組成部分的自定義數據的標準化格式。MIME數據由一個數據類型和一個子類型構成–例如，text/plain，text/html，image/png，要處理自定義MIME數據，就必須要選用一種自定義數據類型和一種子類型，然后將數據封裝到QMimeData對象中。本例子中，我們創建端為application/x-icon-and-text類型的新MIME數據。

注：

dragEnterEvent這是一個拖拽事件的函數，我們把文件拖拽進程序界面打開，之前必須setAcceptDrops(true)了以后拖拽，但是只設置acceptDrops還不夠，還需要在dragEnterEvent事件中對拖入的對象進行篩選，判斷mimeData的類型是否是你能處理的，如果是，則調用event.acceptProposedAction()放行。拖放結束后會產生dropEvent事件，在那里進行最后的放置操作。總之這是拖拽事件函數的一個篩選事件并放置的函數。

第一部分：

#!/usr/bin/env python3import osimport sysfrom PyQt5.QtCore import (QByteArray, QDataStream, QIODevice, QMimeData,    QPoint, QSize, Qt)from PyQt5.QtWidgets import (QApplication, QDialog,QGridLayout,               QLineEdit, QListWidget,QListWidgetItem, QWidget)from PyQt5.QtGui import QIcon,QColor,QPainter,QFontMetricsF,QDragclass DropLineEdit(QLineEdit):  def __init__(self, parent=None):    super(DropLineEdit, self).__init__(parent)    self.setAcceptDrops(True)  def dragEnterEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      event.accept()    else:      event.ignore()  def dragMoveEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      event.setDropAction(Qt.CopyAction)      event.accept()    else:      event.ignore()  def dropEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      data = event.mimeData().data("application/x-icon-and-text")      stream = QDataStream(data, QIODevice.ReadOnly)      text = ""      #stream >> text      text=stream.readQString()      self.setText(text)      event.setDropAction(Qt.CopyAction)      event.accept()    else:      event.ignore()class DnDListWidget(QListWidget):  def __init__(self, parent=None):    super(DnDListWidget, self).__init__(parent)    self.setAcceptDrops(True)    self.setDragEnabled(True)  def dragEnterEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      event.accept()    else:      event.ignore()  def dragMoveEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      event.setDropAction(Qt.MoveAction)      event.accept()    else:      event.ignore()  def dropEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      data = event.mimeData().data("application/x-icon-and-text")      stream = QDataStream(data, QIODevice.ReadOnly)      text = ""      icon = QIcon()      #stream >> text >> icon      text=stream.readQString()      stream >> icon      item = QListWidgetItem(text, self)      item.setIcon(icon)      event.setDropAction(Qt.MoveAction)      event.accept()    else:      event.ignore()  def startDrag(self, dropActions):    item = self.currentItem()    icon = item.icon()    data = QByteArray()    stream = QDataStream(data, QIODevice.WriteOnly)    #stream << item.text() << icon    stream.writeQString(item.text())    stream << icon    mimeData = QMimeData()    mimeData.setData("application/x-icon-and-text", data)    drag = QDrag(self)    drag.setMimeData(mimeData)    pixmap = icon.pixmap(24, 24)    drag.setHotSpot(QPoint(12, 12))    drag.setPixmap(pixmap)    if drag.exec(Qt.MoveAction) == Qt.MoveAction:      self.takeItem(self.row(item))class DnDWidget(QWidget):  def __init__(self, text, icon=QIcon(), parent=None):    super(DnDWidget, self).__init__(parent)    self.setAcceptDrops(True)    self.text = text    self.icon = icon  def minimumSizeHint(self):    fm = QFontMetricsF(self.font())    if self.icon.isNull():      return QSize(fm.width(self.text), fm.height() * 1.5)    return QSize(34 + fm.width(self.text), max(34, fm.height() * 1.5))  def paintEvent(self, event):    height = QFontMetricsF(self.font()).height()    painter = QPainter(self)    painter.setRenderHint(QPainter.Antialiasing)    painter.setRenderHint(QPainter.TextAntialiasing)    painter.fillRect(self.rect(), QColor(Qt.yellow).lighter())    if self.icon.isNull():      painter.drawText(10, height, self.text)    else:      pixmap = self.icon.pixmap(24, 24)      painter.drawPixmap(0, 5, pixmap)      painter.drawText(34, height,               self.text + " (Drag to or from me!)")  def dragEnterEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      event.accept()    else:      event.ignore()  def dragMoveEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      event.setDropAction(Qt.CopyAction)      event.accept()    else:      event.ignore()  def dropEvent(self, event):    if event.mimeData().hasFormat("application/x-icon-and-text"):      data = event.mimeData().data("application/x-icon-and-text")      stream = QDataStream(data, QIODevice.ReadOnly)      self.text = ""      self.icon = QIcon()      #stream >> self.text >> self.icon      self.text=stream.readQString()      stream>>self.icon      event.setDropAction(Qt.CopyAction)      event.accept()      self.updateGeometry()      self.update()    else:      event.ignore()  def mouseMoveEvent(self, event):    self.startDrag()    QWidget.mouseMoveEvent(self, event)  def startDrag(self):    icon = self.icon    if icon.isNull():      return    data = QByteArray()    stream = QDataStream(data, QIODevice.WriteOnly)    #stream << self.text << icon    stream.writeQString(self.text)    stream<<icon    mimeData = QMimeData()    mimeData.setData("application/x-icon-and-text", data)    drag = QDrag(self)    drag.setMimeData(mimeData)    pixmap = icon.pixmap(24, 24)    drag.setHotSpot(QPoint(12, 12))    drag.setPixmap(pixmap)    drag.exec(Qt.CopyAction)class Form(QDialog):  def __init__(self, parent=None):    super(Form, self).__init__(parent)    dndListWidget = DnDListWidget()    path = os.path.dirname(__file__)    for image in sorted(os.listdir(os.path.join(path, "images"))):      if image.endswith(".png"):        item = QListWidgetItem(image.split(".")[0].capitalize())        item.setIcon(QIcon(os.path.join(path,                  "images/{0}".format(image))))        dndListWidget.addItem(item)    dndIconListWidget = DnDListWidget()    dndIconListWidget.setViewMode(QListWidget.IconMode)    dndWidget = DnDWidget("Drag to me!")    dropLineEdit = DropLineEdit()    layout = QGridLayout()    layout.addWidget(dndListWidget, 0, 0)    layout.addWidget(dndIconListWidget, 0, 1)    layout.addWidget(dndWidget, 1, 0)    layout.addWidget(dropLineEdit, 1, 1)    self.setLayout(layout)    self.setWindowTitle("Custom Drag and Drop")if __name__ == "__main__":  app = QApplication(sys.argv)  form = Form()  form.show()  app.exec_()