本文分成两部分，第一部分通过python3+PyQt5实现自定义数据的拖放操作。第二部分则对第一部分的程序进行修改，增加拖放操作时，菜单提示是否移动或拷贝，还有可以通过ctrl键盘来设置移动过程中拷贝源而非会将源删除。

自定义数据MIME数据类型QMimeData，MIME是一种用于处理具有多个组成部分的自定义数据的标准化格式。MIME数据由一个数据类型和一个子类型构成–例如，text/plain，text/html，image/png，要处理自定义MIME数据，就必须要选用一种自定义数据类型和一种子类型，然后将数据封装到QMimeData对象中。本例子中，我们创建端为application/x-icon-and-text类型的新MIME数据。

注：

dragEnterEvent这是一个拖拽事件的函数，我们把文件拖拽进程序界面打开，之前必须setAcceptDrops(true)了以后拖拽，但是只设置acceptDrops还不够，还需要在dragEnterEvent事件中对拖入的对象进行筛选，判断mimeData的类型是否是你能处理的，如果是，则调用event.acceptProposedAction()放行。拖放结束后会产生dropEvent事件，在那里进行最后的放置操作。总之这是拖拽事件函数的一个筛选事件并放置的函数。

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_()

运行结果：

第二部分：

#!/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,QMenu)from PyQt5.QtGui import QIcon,QColor,QPainter,QFontMetricsF,QDrag,QCursorclass 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 = "" text=stream.readQString() self.setText(text) event.setDropAction(Qt.CopyAction) event.accept() else: event.ignore()class DnDMenuListWidget(QListWidget): def __init__(self, parent=None): super(DnDMenuListWidget, self).__init__(parent) self.setAcceptDrops(True) self.setDragEnabled(True) self.dropAction = Qt.CopyAction 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() text=stream.readQString() stream>>icon menu = QMenu(self) menu.addAction("&Copy", self.setCopyAction) menu.addAction("&Move", self.setMoveAction) if menu.exec_(QCursor.pos()): item = QListWidgetItem(text, self) item.setIcon(icon) event.setDropAction(self.dropAction) event.accept() return else: event.setDropAction(Qt.IgnoreAction) event.ignore() def setCopyAction(self): self.dropAction = Qt.CopyAction def setMoveAction(self): self.dropAction = Qt.MoveAction def startDrag(self, dropActions): item = self.currentItem() icon = item.icon() data = QByteArray() stream = QDataStream(data, QIODevice.WriteOnly) 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.CopyAction) == Qt.MoveAction): self.takeItem(self.row(item))class DnDCtrlListWidget(QListWidget): def __init__(self, parent=None): super(DnDCtrlListWidget, 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"): action = Qt.MoveAction if event.keyboardModifiers() & Qt.ControlModifier: action = Qt.CopyAction event.setDropAction(action) 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() text=stream.readQString() stream>>icon item = QListWidgetItem(text, self) item.setIcon(icon) action = Qt.MoveAction if event.keyboardModifiers() & Qt.ControlModifier: action = Qt.CopyAction event.setDropAction(action) event.accept() else: event.ignore() def startDrag(self, dropActions): item = self.currentItem() icon = item.icon() data = QByteArray() stream = QDataStream(data, QIODevice.WriteOnly) 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.CopyAction) == 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() 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.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 = DnDMenuListWidget() 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 = DnDCtrlListWidget() 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_()

运行结果：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。