在后台用大数据集填充 QListview
Populate QListview with large data set in the background
我的工具循环浏览几千张图片并将图片的缩略图加载到我的列表视图中，如下所示。但是，我的应用程序会冻结，直到处理完所有图像。我想知道是否有一种方法可以在加载图像时用图像填充列表视图，防止 UI 冻结并让用户在图像被填充时继续使用应用程序？
这都是我们python和pyside完成的。
代码：
import os
import sys
from PySide import QtGui, QtCore
class Example(QtGui.QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.resize(800, 400)
self.setWindowTitle('Image Viewer')
self.image_dir = "C:/Users/JokerMartini-Asus/Desktop/textures/thumbs"
self.ui_image_viewer = QtGui.QListView()
self.ui_image_viewer.setViewMode(QtGui.QListView.IconMode)
self.ui_image_viewer.setResizeMode(QtGui.QListView.Adjust)
self.ui_image_viewer.setEditTriggers(QtGui.QAbstractItemView.NoEditTriggers)
self.ui_image_viewer.setIconSize(QtCore.QSize(300,300))
self.ui_image_viewer.setMovement(QtGui.QListView.Static)
self.ui_image_viewer.setModel(QtGui.QStandardItemModel())
for img in os.listdir(self.image_dir):
img_path = os.path.join(self.image_dir, img)
pixmap = QtGui.QPixmap(img_path)
name = os.path.splitext(os.path.basename(img_path))[0]
item = QtGui.QStandardItem(QtGui.QIcon(pixmap), name)
self.ui_image_viewer.model().appendRow(item)
# Layout
grid = QtGui.QVBoxLayout()
grid.setContentsMargins(10,10,10,10)
grid.addWidget(self.ui_image_viewer)
main_widget = QtGui.QWidget()
main_widget.setLayout(grid)
self.setCentralWidget(main_widget)
self.show()
def main():
app = QtGui.QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
产生过载的过程是 QPixmap 的创建，因此如果我们随着时间的推移分配该负载，我们可以改善响应，我们可以通过 QTimer 来做到这一点。
import os
import sys
from PySide import QtGui, QtCore
class Example(QtGui.QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.resize(800, 400)
self.setWindowTitle('Image Viewer')
self.image_dir = "C:/Users/JokerMartini-Asus/Desktop/textures/thumbs"
self.ui_image_viewer = QtGui.QListView()
self.ui_image_viewer.setViewMode(QtGui.QListView.IconMode)
self.ui_image_viewer.setResizeMode(QtGui.QListView.Adjust)
self.ui_image_viewer.setEditTriggers(QtGui.QAbstractItemView.NoEditTriggers)
self.ui_image_viewer.setIconSize(QtCore.QSize(300,300))
self.ui_image_viewer.setMovement(QtGui.QListView.Static)
self.ui_image_viewer.setModel(QtGui.QStandardItemModel())
self.imgs = iter(os.listdir(self.image_dir))
timer = QtCore.QTimer(self)
timer.timeout.connect(self.load)
timer.start(100)
# Layout
grid = QtGui.QVBoxLayout()
grid.setContentsMargins(10,10,10,10)
grid.addWidget(self.ui_image_viewer)
main_widget = QtGui.QWidget()
main_widget.setLayout(grid)
self.setCentralWidget(main_widget)
self.show()
def load(self):
try:
img = next(self.imgs)
img_path = os.path.join(self.image_dir, img)
pixmap = QtGui.QPixmap(img_path)
name = os.path.splitext(os.path.basename(img_path))[0]
item = QtGui.QStandardItem(QtGui.QIcon(pixmap), name)
self.ui_image_viewer.model().appendRow(item)
except StopIteration:
self.sender().stop()
def main():
app = QtGui.QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
另一种解决方案是在需要的时候加载图片，也就是移动滚动条的时候，但是为此我们必须覆盖模型的方法数据，并且我们必须创建一个新的角色来存储路径的图像，但分析 QStandardItemModel 的数据逻辑我发现它调用了 SizeHintRole 角色，它调用了角色 DecorationRole，产生了同样的错误，所以我们应该做的是放置一个预定义的大小，这样它就可以避免调用DecorationRole，从而避免重载：
import os
import sys
from PySide.QtCore import *
from PySide.QtGui import *
class StandardItem(QStandardItem):
PathRole = Qt.UserRole +1
def __init__(self, *args, **kwargs):
QStandardItem.__init__(self, *args, **kwargs)
self.path = ""
def setData(self, value, role=Qt.UserRole + 1):
if role == StandardItem.PathRole:
self.path = value
else:
QStandardItem.setData(self, value, role)
# self.emitDataChanged()
def data(self, role=Qt.UserRole+1):
if role == StandardItem.PathRole:
return self.path
return QStandardItem.data(self, role)
def type(self):
return Qt.UserType
class StandardItemModel(QStandardItemModel):
def __init__(self, *args, **kwargs):
QStandardItemModel.__init__(self, *args, **kwargs)
self.setItemPrototype(StandardItem())
def data(self, index, role=Qt.DisplayRole):
if role == Qt.DecorationRole:
it = self.itemFromIndex(index)
value = it.data(Qt.DecorationRole)
if value is None:
path = it.data(StandardItem.PathRole)
value = QIcon(QPixmap(path))
it.setData(value, Qt.DecorationRole)
return value
elif role == Qt.SizeHintRole:
return QSize(300, 250)
else:
return QStandardItemModel.data(self, index, role)
class Example(QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.resize(800, 400)
self.setWindowTitle('Image Viewer')
self.image_dir = "C:/Users/JokerMartini-Asus/Desktop/textures/thumbs"
self.ui_image_viewer = QListView()
self.ui_image_viewer.setViewMode(QListView.IconMode)
self.ui_image_viewer.setResizeMode(QListView.Adjust)
self.ui_image_viewer.setEditTriggers(QAbstractItemView.NoEditTriggers)
self.ui_image_viewer.setIconSize(QSize(300, 300))
self.ui_image_viewer.setMovement(QListView.Static)
self.ui_image_viewer.setModel(StandardItemModel())
for img in os.listdir(self.image_dir):
img_path = os.path.join(self.image_dir, img)
name = os.path.splitext(os.path.basename(img_path))[0]
item = StandardItem(name)
item.setData(img_path)
self.ui_image_viewer.model().appendRow(item)
# Layout
grid = QVBoxLayout()
grid.setContentsMargins(10, 10, 10, 10)
grid.addWidget(self.ui_image_viewer)
main_widget = QWidget()
main_widget.setLayout(grid)
self.setCentralWidget(main_widget)
self.show()
def main():
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
我的工具循环浏览几千张图片并将图片的缩略图加载到我的列表视图中，如下所示。但是，我的应用程序会冻结，直到处理完所有图像。我想知道是否有一种方法可以在加载图像时用图像填充列表视图，防止 UI 冻结并让用户在图像被填充时继续使用应用程序？
这都是我们python和pyside完成的。
代码：
import os
import sys
from PySide import QtGui, QtCore
class Example(QtGui.QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.resize(800, 400)
self.setWindowTitle('Image Viewer')
self.image_dir = "C:/Users/JokerMartini-Asus/Desktop/textures/thumbs"
self.ui_image_viewer = QtGui.QListView()
self.ui_image_viewer.setViewMode(QtGui.QListView.IconMode)
self.ui_image_viewer.setResizeMode(QtGui.QListView.Adjust)
self.ui_image_viewer.setEditTriggers(QtGui.QAbstractItemView.NoEditTriggers)
self.ui_image_viewer.setIconSize(QtCore.QSize(300,300))
self.ui_image_viewer.setMovement(QtGui.QListView.Static)
self.ui_image_viewer.setModel(QtGui.QStandardItemModel())
for img in os.listdir(self.image_dir):
img_path = os.path.join(self.image_dir, img)
pixmap = QtGui.QPixmap(img_path)
name = os.path.splitext(os.path.basename(img_path))[0]
item = QtGui.QStandardItem(QtGui.QIcon(pixmap), name)
self.ui_image_viewer.model().appendRow(item)
# Layout
grid = QtGui.QVBoxLayout()
grid.setContentsMargins(10,10,10,10)
grid.addWidget(self.ui_image_viewer)
main_widget = QtGui.QWidget()
main_widget.setLayout(grid)
self.setCentralWidget(main_widget)
self.show()
def main():
app = QtGui.QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
产生过载的过程是 QPixmap 的创建，因此如果我们随着时间的推移分配该负载，我们可以改善响应，我们可以通过 QTimer 来做到这一点。
import os
import sys
from PySide import QtGui, QtCore
class Example(QtGui.QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.resize(800, 400)
self.setWindowTitle('Image Viewer')
self.image_dir = "C:/Users/JokerMartini-Asus/Desktop/textures/thumbs"
self.ui_image_viewer = QtGui.QListView()
self.ui_image_viewer.setViewMode(QtGui.QListView.IconMode)
self.ui_image_viewer.setResizeMode(QtGui.QListView.Adjust)
self.ui_image_viewer.setEditTriggers(QtGui.QAbstractItemView.NoEditTriggers)
self.ui_image_viewer.setIconSize(QtCore.QSize(300,300))
self.ui_image_viewer.setMovement(QtGui.QListView.Static)
self.ui_image_viewer.setModel(QtGui.QStandardItemModel())
self.imgs = iter(os.listdir(self.image_dir))
timer = QtCore.QTimer(self)
timer.timeout.connect(self.load)
timer.start(100)
# Layout
grid = QtGui.QVBoxLayout()
grid.setContentsMargins(10,10,10,10)
grid.addWidget(self.ui_image_viewer)
main_widget = QtGui.QWidget()
main_widget.setLayout(grid)
self.setCentralWidget(main_widget)
self.show()
def load(self):
try:
img = next(self.imgs)
img_path = os.path.join(self.image_dir, img)
pixmap = QtGui.QPixmap(img_path)
name = os.path.splitext(os.path.basename(img_path))[0]
item = QtGui.QStandardItem(QtGui.QIcon(pixmap), name)
self.ui_image_viewer.model().appendRow(item)
except StopIteration:
self.sender().stop()
def main():
app = QtGui.QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
另一种解决方案是在需要的时候加载图片，也就是移动滚动条的时候，但是为此我们必须覆盖模型的方法数据，并且我们必须创建一个新的角色来存储路径的图像，但分析 QStandardItemModel 的数据逻辑我发现它调用了 SizeHintRole 角色，它调用了角色 DecorationRole，产生了同样的错误，所以我们应该做的是放置一个预定义的大小，这样它就可以避免调用DecorationRole，从而避免重载：
import os
import sys
from PySide.QtCore import *
from PySide.QtGui import *
class StandardItem(QStandardItem):
PathRole = Qt.UserRole +1
def __init__(self, *args, **kwargs):
QStandardItem.__init__(self, *args, **kwargs)
self.path = ""
def setData(self, value, role=Qt.UserRole + 1):
if role == StandardItem.PathRole:
self.path = value
else:
QStandardItem.setData(self, value, role)
# self.emitDataChanged()
def data(self, role=Qt.UserRole+1):
if role == StandardItem.PathRole:
return self.path
return QStandardItem.data(self, role)
def type(self):
return Qt.UserType
class StandardItemModel(QStandardItemModel):
def __init__(self, *args, **kwargs):
QStandardItemModel.__init__(self, *args, **kwargs)
self.setItemPrototype(StandardItem())
def data(self, index, role=Qt.DisplayRole):
if role == Qt.DecorationRole:
it = self.itemFromIndex(index)
value = it.data(Qt.DecorationRole)
if value is None:
path = it.data(StandardItem.PathRole)
value = QIcon(QPixmap(path))
it.setData(value, Qt.DecorationRole)
return value
elif role == Qt.SizeHintRole:
return QSize(300, 250)
else:
return QStandardItemModel.data(self, index, role)
class Example(QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.resize(800, 400)
self.setWindowTitle('Image Viewer')
self.image_dir = "C:/Users/JokerMartini-Asus/Desktop/textures/thumbs"
self.ui_image_viewer = QListView()
self.ui_image_viewer.setViewMode(QListView.IconMode)
self.ui_image_viewer.setResizeMode(QListView.Adjust)
self.ui_image_viewer.setEditTriggers(QAbstractItemView.NoEditTriggers)
self.ui_image_viewer.setIconSize(QSize(300, 300))
self.ui_image_viewer.setMovement(QListView.Static)
self.ui_image_viewer.setModel(StandardItemModel())
for img in os.listdir(self.image_dir):
img_path = os.path.join(self.image_dir, img)
name = os.path.splitext(os.path.basename(img_path))[0]
item = StandardItem(name)
item.setData(img_path)
self.ui_image_viewer.model().appendRow(item)
# Layout
grid = QVBoxLayout()
grid.setContentsMargins(10, 10, 10, 10)
grid.addWidget(self.ui_image_viewer)
main_widget = QWidget()
main_widget.setLayout(grid)
self.setCentralWidget(main_widget)
self.show()
def main():
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()