xcode 6，ios 8，object-C ++

Question

I create a new app project(not library or framework), and then I set "compile source as" as object-C++.But when I compile the source, it shows “build failed”.

The error is :

Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_UIResponder", referenced from:
      _OBJC_CLASS_$_AppDelegate in AppDelegate.o
  "_OBJC_METACLASS_$_UIResponder", referenced from:
      _OBJC_METACLASS_$_AppDelegate in AppDelegate.o
  "_UIApplicationMain", referenced from:
      _main in main.o
  "_OBJC_METACLASS_$_UIViewController", referenced from:
      _OBJC_METACLASS_$_ViewController in ViewController.o
  "_OBJC_CLASS_$_UIViewController", referenced from:
      _OBJC_CLASS_$_ViewController in ViewController.o
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

but what makes me confused is that : if it is a framework project,it compiles well. Could you lend me a hand !

Answer 1

Your app's missing symbols from UIKit. You need to link your app to UIKit:

• Select the project in the project navigator (cmd+1, top left in left panel)
• Select the target (ie your app) under TARGETS
• Click "Build Phases" tab
• Click the "Link Binary with Libraries" disclosure triangle, unless the table is already visible
• Click the '+' at the bottom of the table
• Double click UIKit.framework to add it to your link stage

Once that is completed, there may be new link issues which are discovered.