python3+PyQt5重新实现自定义数据拖放处理
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 python3
import os
import sys
from 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,QDrag
class 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 python3
import os
import sys
from 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,QCursor
class 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【听图阁-专注于Python设计】。
