是否可以使用PySide2有条件地更改QTableView中项目的背景颜色？我在model view framework上读了很多。我无法弄清楚是否有必要使用代表。最近，我得到了一列没有代表的复选框。我相信虚拟方法setItemData(index, roles)和itemData(index)可能是我需要的。但是，PySide2中没有QMap。我的模型必须在某个地方存储QtCore.Qt.BackgroundRole使用的额外信息（枚举，顺便说一句，“用于使用默认委托呈现的项目的背景画笔”）如果我没有指定委托，则是“默认委托” “ 用过的？。我应该使用QStandardItemModel吗？在下面的示例代码中，如何根据某些阈值将特定列的背景颜色设置为红色（最小和最大列是阈值？
from PySide2.QtWidgets import (QWidget, QApplication, QTableView,QVBoxLayout)
import sys
from PandasModel2 import PandasModel2
import numpy as np
import pandas as pd
class Example(QWidget):
def __init__(self):
super().__init__()
self.setGeometry(300, 300, 700, 300)
self.setWindowTitle("QTableView")
self.initData()
self.initUI()
def initData(self):
data = pd.DataFrame(np.random.randint(1,10,size=(6,4)), columns=['Test#','MIN', 'MAX','MEASURED'])
data['Test#'] = [1,2,3,4,5,6]
#add the checkable column to the DataFrame
data['Check'] = True
self.model = PandasModel2(data)
def initUI(self):
self.tv = QTableView(self)
self.tv.setModel(self.model)
vbox = QVBoxLayout()
vbox.addWidget(self.tv)
self.setLayout(vbox)
app = QApplication([])
ex = Example()
ex.show()
sys.exit(app.exec_())
我有一个使用pandas dataFrame的自定义模型：
import PySide2.QtCore as QtCore
class PandasModel2(QtCore.QAbstractTableModel):
"""
Class to populate a table view with a pandas dataframe.
This model is non-hierachical.
"""
def __init__(self, data, parent=None):
QtCore.QAbstractTableModel.__init__(self, parent)
self._data = data
def rowCount(self, parent=None):
return self._data.shape[0]
def columnCount(self, parent=None):
return self._data.shape[1]
def data(self, index, role=QtCore.Qt.DisplayRole):
if role==QtCore.Qt.DisplayRole:
if index.column() != 4:
#don't want what determines check state to be shown as a string
if index.isValid():
if index.column() in [1,2,3]:
return '{:.3f}'.format(self._data.iloc[index.row(), index.column()])
if index.column() == 0:
return '{:.2f}'.format(self._data.iloc[index.row(), index.column()])
return str(self._data.iloc[index.row(), index.column()])
if role==QtCore.Qt.CheckStateRole:
if index.column()==4:#had to add this check to get the check boxes only in column 10
if self._data.iloc[index.row(), index.column()] == True:
return QtCore.Qt.Checked
else:
return QtCore.Qt.Unchecked
def getMinimum(self, row):
return self._data.iloc[row, self.getColumnNumber('MIN')]
def getMaximum(self, row):
return self._data.iloc[row, self.getColumnNumber('MAX')]
def getColumnNumber(self, string):
'''
Given a string that identifies a label/column,
return the location of that label/column.
This enables the config file columns to be moved around.
'''
return self._data.columns.get_loc(string)
def headerData(self, col, orientation, role):
if orientation == QtCore.Qt.Horizontal and role == QtCore.Qt.DisplayRole:
return self._data.columns[col]
return None
def flags(self, index):
'''
The returned enums indicate which columns are editable, selectable,
checkable, etc.
The index is a QModelIndex.
'''
if index.column() == self.getColumnNumber('Check'):
#print(index.column())
return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsUserCheckable
else:
return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsEditable
return QtCore.Qt.ItemIsEnabled
def setData(self, index, value, role=QtCore.Qt.DisplayRole):
"""Set the value to the index position depending on Qt::ItemDataRole and data type of the column
Args:
index (QtCore.QModelIndex): Index to define column and row.
value (object): new value.
role (Qt::ItemDataRole): Use this role to specify what you want to do.
Raises:
TypeError: If the value could not be converted to a known datatype.
Returns:
True if value is changed. Calls layoutChanged after update.
False if value is not different from original value.
"""
if not index.isValid():
return False
if role == QtCore.Qt.DisplayRole: #why not edit role?
self._data.iat[index.row(),index.column()]= value
self.layoutChanged.emit()
return True
elif role == (QtCore.Qt.CheckStateRole | QtCore.Qt.DisplayRole):
#this block does get executed when toggling the check boxes,
#verified with debugger. Although the action is the same
#as the block above!
self._data.iat[index.row(),index.column()]= value
self.layoutChanged.emit()
return True
else:
return False
默认情况下，委托使用BackgroundRole信息（如果可用），因此解决方案只是返回QColor，QBrush或类似信息。
from PySide2 import QtCore, QtGui
class PandasModel2(QtCore.QAbstractTableModel):
# ...
def data(self, index, role=QtCore.Qt.DisplayRole):
if not index.isValid():
return
if not (0 <= index.row() < self.rowCount() and 0 <= index.column() <= self.columnCount()):
return
value = self._data.iloc[index.row(), index.column()]
if role == QtCore.Qt.DisplayRole:
if index.column() != 4:
if index.column() in [1,2,3]:
return '{:.3f}'.format(value)
if index.column() == 0:
return '{:.2f}'.format(value)
return str(value)
elif role == QtCore.Qt.CheckStateRole:
if index.column() == 4:
return QtCore.Qt.Checked if value else QtCore.Qt.Unchecked
elif index.column() == self.getColumnNumber('MEASURED'):
if role == QtCore.Qt.BackgroundRole:
if self.getMinimum(index.row()) <= value <= self.getMaximum(index.row()):
return QtGui.QColor("red")