使用代理模型在更改值后更改 QTableView 的单元格背景颜色

Question

我有一个子类化QAbstractTableModel

包含 None 类型值以将行显示为空

class ViewModel(qtc.QAbstractTableModel):
def __init__(self, input_data=None):
super().__init__()
self.input_data = input_data or [[None, None],[None, None]]

如果插入的值(替换无类型值(在某个范围内/超出某个范围，我想更改单元格的颜色

喜欢z = 12 <= x <= 20

# False == red, True == green

仅当项目被编辑或self.model.layoutChanged.emit()被执行

更改 QTableView 的单元格背景颜色的答案建议在数据方法中进行更改 如何更改 QTableView 的单元格背景颜色 [重复] 但这会在开始时为细胞着色

我在QT论坛中找到了一种在视图和模型之间插入代理模型的方法 如何简单地更改表格视图中单元格的背景颜色

我正在尝试将代码实现到 Pyqt5 中，但到目前为止没有成功。有没有我不知道的 PyQt5 方法？

示例代码

import sys
import re
from PyQt5 import QtWidgets as qtw
from PyQt5 import QtCore as qtc

class ViewModel(qtc.QAbstractTableModel):
def __init__(self, input_data=None):
super().__init__()
self.input_data = input_data or [[None, None],[None, None]]

def data(self, index, role):  # parameter index, role are needed !
if role == qtc.Qt.DisplayRole:
try:
text = self.input_data[index.row()][index.column()]
except IndexError:
text = None
return text
def rowCount(self, index=qtc.QModelIndex()):
return 0 if index.isValid() else len(self.input_data)

def columnCount(self, index):
return len(self.input_data[0])
def headerData(self, section, orientation, role):
# section is which index of the orientation
if role == qtc.Qt.DisplayRole:
if orientation == qtc.Qt.Vertical:
return "row"
def flags(self, index):
return qtc.Qt.ItemIsEditable | qtc.Qt.ItemIsSelectable | qtc.Qt.ItemIsEnabled
def setData(self, index, value, role=qtc.Qt.EditRole):
if role == qtc.Qt.EditRole:
try:
row = index.row()
column = index.column()
pattern = '^[d]+(?:,[d]+)?$'

if re.fullmatch(pattern, value, flags=0):
print("true")
self.input_data[row][column] = value  # float
else:
print("nope")
pass
return True
except ValueError:
print("not a number")
return False

class MainWindow(qtw.QWidget):

def __init__(self):
super().__init__()
# View
table_view = qtw.QTableView()
self.model = ViewModel()
table_view.setModel(self.model)
# size and position
qtRectangle = self.frameGeometry()
centerPoint = qtw.QDesktopWidget().availableGeometry().center()
qtRectangle.moveCenter(centerPoint)
self.move(qtRectangle.topLeft())
# size
self.resize(1000, 410)
# layout
qvboxlayout = qtw.QVBoxLayout()
qvboxlayout.addWidget(table_view)
self.setLayout(qvboxlayout)
self.show()

if __name__ == '__main__':
app = qtw.QApplication(sys.argv)
w = MainWindow()
sys.exit(app.exec_())

Answer 1

如果要使用代理更改颜色，则只应覆盖data()方法：

class ColorProxy(qtc.QIdentityProxyModel):
def data(self, index, role=qtc.Qt.DisplayRole):
if role == qtc.Qt.BackgroundRole:
data = index.data()
try:
value = float(data)
except (ValueError, TypeError) as e:
print("error:", e)
else:
return qtg.QColor("green") if 12 <= value <= 20 else qtg.QColor("red")
return super().data(index, role)

# ...
self.model = ViewModel()
proxy = ColorProxy()
proxy.setSourceModel(self.model)
table_view.setModel(proxy)
# ...

另一种解决方案是使用委托

class ColorDelegate(qtw.QStyledItemDelegate):
def initStyleOption(self, option, index):
super().initStyleOption(option, index)
data = index.data()
try:
value = float(data)
except (ValueError, TypeError) as e:
print("error:", e)
else:
color = qtg.QColor("green") if 12 <= value <= 20 else qtg.QColor("red")
option.backgroundBrush = color

# ...
table_view = qtw.QTableView()
self.model = ViewModel()
delegate = ColorDelegate(table_view)
table_view.setItemDelegate(delegate)
table_view.setModel(self.model)
# ...