如何向 QTreeWidgetItem 添加彩色动画？

Question

我需要为 QTreeWidgetItem 添加彩色动画，但在我的代码中，它引发了一些错误，谁能帮助我？

代码示例在这里：

class TreeWigetItem(QTreeWidgetItem):
    def __init__(self, parent=None):
        super().__init__(parent)

    @pyqtProperty(QBrush)
    def bcolor(self):
        return self.background(0)

    @bcolor.setter
    def bcolor(self, color):
        self.setBackground(0, color)
        self.setBackground(1, color)

并像这样调用方法：

child_item = TreeWigetItem()
self.child_item_ani = QPropertyAnimation(child_item, b'bcolor')
self.child_item_ani.setDuration(1000)
self.child_item_ani.setEndValue(QBrush(Qt.red))
self.child_item_ani.start()

这里有错误：

self.child_item_ani = QPropertyAnimation(child_item, b'bcolor')  
TypeError: arguments did not match any overloaded call:  
  QPropertyAnimation(parent: QObject = None): argument 1 has unexpected type 'TreeWigetItem'  
  QPropertyAnimation(QObject, Union[QByteArray, bytes, bytearray], parent: QObject = None): argument 1 has unexpected type 'TreeWigetItem'  

Answer 1

Property(PyQt 中的 pyqtProperty) 仅在 QObjects 中有效，但在这种情况下，QTreeWidgetItem 不继承自 QObject，因此 QPropertyAnimation 也不起作用。因此，您应该使用QVariantAnimation，而不是使用QPropertyAnimation，如下所示：

import os
from PyQt5 import QtCore, QtGui, QtWidgets


class TreeWidgetItem(QtWidgets.QTreeWidgetItem):
    @property
    def animation(self):
        if not hasattr(self, "_animation"):
            self._animation = QtCore.QVariantAnimation()
            self._animation.valueChanged.connect(self._on_value_changed)
        return self._animation

    def _on_value_changed(self, color):
        for i in range(self.columnCount()):
            self.setBackground(i, color)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)

    w = QtWidgets.QTreeWidget(columnCount=2)

    it = TreeWidgetItem(["Foo", "Bar"])

    # setup animation
    it.animation.setStartValue(QtGui.QColor("white"))
    it.animation.setEndValue(QtGui.QColor("red"))
    it.animation.setDuration(5 * 1000)
    it.animation.start()

    # add item to QTreeWidget
    w.addTopLevelItem(it)

    w.show()
    sys.exit(app.exec_())