UI项目未显示在界面构建器中

Question

I have a strange issue here about interface builder. I added some views, buttons to my view controller and they were displayed well in the interface builder some hours before. But now, they disappeared. I mean, they are not displayed in the interface builder while showing up perfectly when running. Below images is the view controller in my interface builder.

Here is some other view controller in the same project. Items in it are showing normally.

Could anyone tell me the reason of this ?

EDIT: They disappeared after I installed some libraries using cocoapods. Can it be the reason?

Answer 1

Check the size class，you may add views in one size class and see it in another

Also,selected the hidden view to check if it is installed in this size class