如何在Xcode Interface Builder中显示占位符背景？

Question

How do I set and show custom Placeholder Backgrounds in Xcode 7's Interface Builder?

This functionality was added in Xcode 7 , but I can't the way to set it.

Background placeholders on custom views and other containers can be hidden on the Interface Builder canvas by selecting Editor > Canvas > Show Background Placeholders. (20580948)

I've enabled in but nothing changed and I can't find where I can set a custom placeholder image:

Answer 1

A few years later and Xcode 10 still doesn't provide any of the flexibility you had in mind back then 😐

From Xcode 10 documentation:

Use placeholder backgrounds to identify image views, MapKit views, MetalKit views, GLKit views, and SceneKit views. Hide the placeholder backgrounds to focus on the content of your own views.

Choose Editor > Canvas > Show Placeholder Backgrounds to toggle showing placeholder backgrounds for certain types of views on the Interface Builder canvas.

The feature really is limited to only some of the built-in views from Apple (and even those that blue-ish background color is still pretty much hardcoded).