如何立即检测QTreeView中的复选框状态更改？

from PyQt5.QtWidgets import QApplication, QTreeView, QStandardItemModel, QStandardItem
from PyQt5.QtCore import Qt

def on_selection_changed(selected, deselected):
    for index in selected.indexes():
        item = model.itemFromIndex(index)
        if item.checkState() == Qt.Checked:
            print("复选框被选中")
        else:
            print("复选框被取消选中")

app = QApplication([])
tree_view = QTreeView()
model = QStandardItemModel()
tree_view.setModel(model)

# 添加根节点
root_item = QStandardItem("根节点")
root_item.setCheckable(True)
model.appendRow(root_item)

# 添加子节点
child_item = QStandardItem("子节点")
child_item.setCheckable(True)
root_item.appendRow(child_item)

# 连接信号和槽
selection_model = tree_view.selectionModel()
selection_model.selectionChanged.connect(on_selection_changed)

tree_view.show()
app.exec_()