| id | 层级视图项标识符。 |
| outChildren | 使用项的子项标识符填充的列表（作为方法调用的结果）。 |
获取层级视图项的子项的列表。
The result is written to outChildren list which is resized if necessary.
The list contains identifiers of item children in order defined by sorting parameters.
Identifier defines a specific tree view item in the current frame hierarchy. Different frames have different identifiers for the tree items.
GetItemChildren 调用会构建下一个层级视图级别，使子项数据可供获取。
另请参阅：TreeViewItem.children。