python3+PyQt5重新实现自定义数据拖放处理

Python  /  管理员 发布于 7年前   132

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C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：

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