| child | 应设置新父项的游戏对象。 |
| parent | 子项应作为父项获取且具有从中复制的位置和层的游戏对象。如果为 null，此函数不执行任何操作。 |
设置父项，并为子项提供相同的层和位置。
This is intended as a utility function when creating custom GameObjects with a MenuItem in the "GameObject/" menu. When using the context click menu to create new GameObjects in the Scene hierarchy, the newly created GameObjects should be parented to the clicked GameObject, which is passed in as MenuCommand.context. Calling this method ensures this behavior in the case of a context click while doing nothing if the context is null (see example on the MenuItem docs).