You would store a font preference in the user tree, as that is a user-specific issue.
您要将字体首选项存储在用户树中，因为这是用户特定的内容。
2
When you change a font, you can create a new UITextField at the same time. Or, you can store the new font context and a flag indicating that fonts have changed.
In fact, the name itself indicates this: a common use for it is to store user-specific Settings, or preferences, such as font size or window layout. (Of course, you can store anything you want in it.)