Categories in Objective-C aren't working

Question

I\'m developing an iOS application that needs to deploy to iOS 3.1.3. I need to extend some of the functionality of the NSData class and am using the following code inside N

Answer 1

In My case when I got this error I simply added the .m file in the Compiled resources, and it get worked. This can be achieved by selecting target project->Build Phases->Compile Sources. Then you click on the + button from its bottom left. In this case you may add 'NSData+Base64.m' file to the compile sources. Then you clean your project and run. I guess this may help.