ios - Xcode "Size to fit contents" disabled

Question

I am following the Stanford lectures on developing apps for iOS and I've run into a bit of a problem. The lecturer says to click on a label from the Document Outline and then go to Editor > Size to fit contents in order to remove the fixed size constraints. However my problem is that "Size to fit contents" is disabled and I cannot click it (see image).

Any idea what I'm doing wrong?

Answer 1

我通过拖动标签并手动（随机）调整它们的大小来解决问题，然后启用该选项！

Answer 2

好的，这是困扰我一段时间的问题。但我终于发现，如果您点击标签的一个角手柄（您将短暂看到一个用于调整大小的对角线鼠标图标），那么“大小以适应内容”选项将重新启用。

如果您点击视图的角手柄之一，这也适用于获取“水平规则”和“垂直规则”选项。