修复 QTreeWidget 上的选定项目荧光笔

Question

我有一个 QTreeWidget，里面有值，我只想显示一定数量的小数，但为了计算目的保持精度。我让它正常工作，但所选项目的突出显示混乱，并在已绘制的单元格周围显示白色。

如何修复突出显示，使整行都显示为纯蓝色？

class InitialDelegate(QtWidgets.QItemDelegate):
    'Changes number of decimal places in gas analysis self.chosen table'
    def __init__(self, decimals, parent=None):
        super().__init__(parent)
        self.nDecimals = decimals
    def paint(self, painter, option, index):
        if index.column() == 1:
            value = index.model().data(index, QtCore.Qt.DisplayRole)
            try:
                number = float(value)
                painter.drawText(option.rect, QtCore.Qt.AlignCenter , "{:.{}f}".format(number, self.nDecimals))
            except:
                QtWidgets.QItemDelegate.paint(self, painter, option, index)
        else:
            QtWidgets.QItemDelegate.paint(self, painter, option, index)

这是它产生的结果：

Answer 1

我在实施过程中有 2 个观察结果：

如果您只想更改文本显示的格式，那么您不应该覆盖 paint() method since it not only paints the text but also the background, icons, etc. The drawDisplay() 方法必须被覆盖。
如果您只想将更改应用于列，最好使用 setItemDelegateForColumn() 方法设置委托

综合以上，则解法为：

from PyQt5 import QtCore, QtGui, QtWidgets


class InitialDelegate(QtWidgets.QItemDelegate):
    "Changes number of decimal places in gas analysis self.chosen table"

    def __init__(self, decimals, parent=None):
        super().__init__(parent)
        self.nDecimals = decimals

    def drawDisplay(self, painter, option, rect, text):
        option.displayAlignment = QtCore.Qt.AlignCenter
        try:
            number = float(text)
            text = "{:.{}f}".format(number, self.nDecimals)
        except:
            pass
        super().drawDisplay(painter, option, rect, text)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = QtWidgets.QTreeWidget(columnCount=3)
    delegate = InitialDelegate(2, w)
    w.setItemDelegateForColumn(1, delegate) # <---
    w.setHeaderLabels(["Gas Component", "Molecular Weight", "Mol%"])
    it = QtWidgets.QTreeWidgetItem(["Hexane", "86.1777", ""])
    w.addTopLevelItem(it)
    w.show()
    sys.exit(app.exec_())

加上：

如果你想做同样的事情但使用 QStyledItemDelegate then the solution is override initStyleOption():

class InitialDelegate(QtWidgets.QStyledItemDelegate):
    "Changes number of decimal places in gas analysis self.chosen table"

    def __init__(self, decimals, parent=None):
        super().__init__(parent)
        self.nDecimals = decimals

    def initStyleOption(self, option, index):
        super().initStyleOption(option, index)
        option.displayAlignment = QtCore.Qt.AlignCenter
        try:
            text = index.model().data(index, QtCore.Qt.DisplayRole)
            number = float(text)
            option.text = "{:.{}f}".format(number, self.nDecimals)
        except:
            pass

修复 QTreeWidget 上的选定项目荧光笔

Fix selected item highlighter on QTreeWidget

python

python-3.x

pyqt

pyqt5

qtreewidget