An error occurred while running in OC (Unknown class & lt; XXX & gt; in InterfaceBuilder file.) solution: interfacebuilder

An error occurred while running in OC (Unknown class <XXX> in InterfaceBuilder file.) solution: interfacebuilder

For a classroom exercise, the login window of a single view is always smooth, and an error occurs during compilation and running. All the space is not displayed. After checking for a long time, I asked the training teacher to solve the problem. I would like to record the solution.

Unknown class <XXX> in InterfaceBuilder file.

Symptom:

Link error: Unknown class <XXClass> in Interface Builder file. XXClass does exist and has no problems.

See http://stackoverflow.com/questions/1725881/unknown-class-myclass-in-interface-builder-file-error-at-runtime

Cause: Because XXClass is only referenced in the nib file and not referenced elsewhere, it is optimized by link. runtime errors occur when the nib file tries to load XXClass.

Solution:

Specify-all_load-ObjC in A. link flag

B. Reference XXClass at a time, for example, [XXClassclass]

C. Delete the XXClass file in the project and add it again.

 

The third method is feasible.