unrecognized selector sent to instance

Question

I added an index search to a core data backed UITableView. the search works fine, however after navigating back to the tableView I get this error:

-[NSSQLRow controllerDidChangeContent:]: unrecognized selector sent to instance 0x815edf0

I can post more code if this is too little information to go on.

thanks for any help

Answer 1

In Xcode (3), enable:

Run > Stop on Objective-C Exceptions

run your program in Debug.

Ultimately what is happening is an (objc) object is requested to perform a message which it does not respond to (i.e. is not implemented).

Typically, this happens as a programmer's mistake (at least, for me), such as an argument passed as another type, which slips through a cast, id, or objc_object container (e.g. any collection class - NSArray, NSSet, NSDictionary).

Sometimes this happens if you forget to implement the instance method.

Sometimes this happens if you are testing against an earlier release of the software, which did not implement the instance method (i.e. it was added in a following release).