构建失败错误：未定义的符号

Question

I am getting this error when I try to build my project.

Undefined symbols for architecture i386:
  "_OBJC_IVAR_$_UINavigationBar.images", referenced from:
      -[UINavigationBar(CustomImage) drawRect:] in AppDelegate.o
      -[UINavigationBar(CustomImage) setImagesNames:] in AppDelegate.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Anyone can help?

Answer 1

Go to your AppDelegate class and check the include for your UINavigationBar category. Your category is either missing from the project, or it is private. My best guess is that it's missing or when you created it you didn't check the target checkbox. They removing it and re-add it. Be careful when you add it back to have your active target checked for the file.