加载或倾倒泡菜时如何阻止动画 QCursor 冻结？
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【中文标题】加载或倾倒泡菜时如何阻止动画 QCursor 冻结？【英文标题】：How to stop an animated QCursor from freezing when loading or dumping with pickle? 【发布时间】：2019-11-29 13:42:56 【问题描述】：作为this帖子的后续问题，我想知道是否可以扩展光标的功能，以便在使用pickle转储或保存数据时，光标的动画不会冻结.
from PyQt5 import QtCore, QtGui, QtWidgets
import pickle
import gzip
import numpy as np
class ManagerCursor(QtCore.QObject):
def __init__(self, parent=None):
super(ManagerCursor, self).__init__(parent)
self._movie = None
self._widget = None
self._last_cursor = None
def setMovie(self, movie):
if isinstance(self._movie, QtGui.QMovie):
if not self._movie != QtGui.QMovie.NotRunning:
self._movie.stop()
del self._movie
self._movie = movie
self._movie.frameChanged.connect(self.on_frameChanged)
self._movie.started.connect(self.on_started)
self._movie.finished.connect(self.restore_cursor)
def setWidget(self, widget):
self._widget = widget
@QtCore.pyqtSlot()
def on_started(self):
if self._widget is not None:
self._last_cursor = self._widget.cursor()
@QtCore.pyqtSlot()
def restore_cursor(self):
if self._widget is not None:
if self._last_cursor is not None:
self._widget.setCursor(self._last_cursor)
self._last_cursor = None
@QtCore.pyqtSlot()
def start(self):
if self._movie is not None:
self._movie.start()
@QtCore.pyqtSlot()
def stop(self):
if self._movie is not None:
self._movie.stop()
self.restore_cursor()
@QtCore.pyqtSlot()
def on_frameChanged(self):
pixmap = self._movie.currentPixmap()
cursor = QtGui.QCursor(pixmap)
if self._widget is not None:
if self._last_cursor is None:
self._last_cursor = self._widget.cursor()
self._widget.setCursor(cursor)
class Progress(QtWidgets.QDialog):
def __init__(self):
super().__init__()
progress = QtWidgets.QProgressBar()
lay = QtWidgets.QVBoxLayout(self)
lay.addWidget(progress)
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
start_btn = QtWidgets.QPushButton("start", clicked=self.on_start)
stop_btn = QtWidgets.QPushButton("stop", clicked=self.on_stop)
dump_btn = QtWidgets.QPushButton("dump", clicked=self.dump)
load_btn = QtWidgets.QPushButton("load", clicked=self.load)
self.file = 'test'
text_edit = QtWidgets.QTextEdit()
self.popup = None
self._manager = ManagerCursor(self)
movie = QtGui.QMovie('../assets/comet_resized.gif')
self._manager.setMovie(movie)
self._manager.setWidget(self)
lay = QtWidgets.QVBoxLayout(self)
lay.addWidget(start_btn)
lay.addWidget(stop_btn)
lay.addWidget(dump_btn)
lay.addWidget(load_btn)
lay.addWidget(text_edit)
lay.addStretch()
@QtCore.pyqtSlot()
def dump(self):
self._manager.start()
self.popup = Progress()
self.popup.show()
data = [np.full(1000, 1000) for i in range(100000)]
with gzip.open(self.file, 'wb') as output_file:
pickle.dump(data, output_file, pickle.HIGHEST_PROTOCOL)
def load(self):
self._manager.start()
self.popup = Progress()
self.popup.show()
with gzip.open(self.file, 'rb') as input_file:
data = pickle.load(input_file)
@QtCore.pyqtSlot()
def on_start(self):
self._manager.start()
@QtCore.pyqtSlot()
def on_stop(self):
self._manager.stop()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
【问题讨论】：
【参考方案1】：繁重的任务不应该在主线程中执行，因为它们会通过冻结 GUI 来阻塞事件循环，它必须在另一个线程中执行。
from functools import partial
import gzip
import pickle
from PyQt5 import QtCore, QtGui, QtWidgets
import numpy as np
class Worker(QtCore.QObject):
dumpStarted = QtCore.pyqtSignal()
dumpFinished = QtCore.pyqtSignal()
dataChanged = QtCore.pyqtSignal(object)
loadStarted = QtCore.pyqtSignal()
loadFinished = QtCore.pyqtSignal()
@QtCore.pyqtSlot(str, object)
def dump(self, filename, data):
self.dumpStarted.emit()
with gzip.open(filename, "wb") as output_file:
pickle.dump(data, output_file, pickle.HIGHEST_PROTOCOL)
self.dumpFinished.emit()
@QtCore.pyqtSlot(str)
def load(self, filename):
self.loadStarted.emit()
with gzip.open(filename, "rb") as input_file:
data = pickle.load(input_file)
self.dataChanged.emit(data)
self.loadFinished.emit()
class ManagerCursor(QtCore.QObject):
def __init__(self, parent=None):
super(ManagerCursor, self).__init__(parent)
self._movie = None
self._widget = None
self._last_cursor = None
def setMovie(self, movie):
if isinstance(self._movie, QtGui.QMovie):
if not self._movie != QtGui.QMovie.NotRunning:
self._movie.stop()
del self._movie
self._movie = movie
self._movie.frameChanged.connect(self.on_frameChanged)
self._movie.started.connect(self.on_started)
self._movie.finished.connect(self.restore_cursor)
def setWidget(self, widget):
self._widget = widget
@QtCore.pyqtSlot()
def on_started(self):
if self._widget is not None:
self._last_cursor = self._widget.cursor()
@QtCore.pyqtSlot()
def restore_cursor(self):
if self._widget is not None:
if self._last_cursor is not None:
self._widget.setCursor(self._last_cursor)
self._last_cursor = None
@QtCore.pyqtSlot()
def start(self):
if self._movie is not None:
self._movie.start()
@QtCore.pyqtSlot()
def stop(self):
if self._movie is not None:
self._movie.stop()
self.restore_cursor()
@QtCore.pyqtSlot()
def on_frameChanged(self):
pixmap = self._movie.currentPixmap()
cursor = QtGui.QCursor(pixmap)
if self._widget is not None:
if self._last_cursor is None:
self._last_cursor = self._widget.cursor()
self._widget.setCursor(cursor)
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
start_btn = QtWidgets.QPushButton("start", clicked=self.on_start)
stop_btn = QtWidgets.QPushButton("stop", clicked=self.on_stop)
dump_btn = QtWidgets.QPushButton("dump", clicked=self.dump)
load_btn = QtWidgets.QPushButton("load", clicked=self.load)
self.file = "test"
text_edit = QtWidgets.QTextEdit()
self.popup = None
self._manager = ManagerCursor(self)
movie = QtGui.QMovie("giphy.gif")
self._manager.setMovie(movie)
self._manager.setWidget(self)
lay = QtWidgets.QVBoxLayout(self)
lay.addWidget(start_btn)
lay.addWidget(stop_btn)
lay.addWidget(dump_btn)
lay.addWidget(load_btn)
lay.addWidget(text_edit)
lay.addStretch()
thread = QtCore.QThread(self)
thread.start()
self._worker = Worker()
self._worker.moveToThread(thread)
self._worker.dumpStarted.connect(self._manager.start)
self._worker.dumpFinished.connect(self._manager.stop)
self._worker.dumpStarted.connect(partial(dump_btn.setEnabled, False))
self._worker.dumpFinished.connect(partial(dump_btn.setEnabled, True))
self._worker.loadStarted.connect(self._manager.start)
self._worker.loadFinished.connect(self._manager.stop)
self._worker.loadStarted.connect(partial(load_btn.setEnabled, False))
self._worker.loadFinished.connect(partial(load_btn.setEnabled, True))
self._worker.dataChanged.connect(self.on_data_changed)
@QtCore.pyqtSlot()
def dump(self):
data = [np.full(1000, 1000) for i in range(100000)]
wrapper = partial(self._worker.dump, self.file, data)
QtCore.QTimer.singleShot(0, wrapper)
@QtCore.pyqtSlot()
def load(self):
wrapper = partial(self._worker.load, self.file)
QtCore.QTimer.singleShot(0, wrapper)
@QtCore.pyqtSlot(object)
def on_data_changed(self, data):
print(data)
@QtCore.pyqtSlot()
def on_start(self):
self._manager.start()
@QtCore.pyqtSlot()
def on_stop(self):
self._manager.stop()
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
【讨论】：
感谢您的回答！我实现了类似的东西并且它有效！我也尝试将光标移动到另一个线程，但我无法让它工作。我真的不明白为什么。 @mapf 见doc.qt.io/qt-5/thread-basics.html#gui-thread-and-worker-thread 为什么要添加partial 方法？您基本上不是在您的连接语句中定义新功能吗？从外面怎么称呼他们？以上是关于加载或倾倒泡菜时如何阻止动画 QCursor 冻结？的主要内容，如果未能解决你的问题，请参考以下文章
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