Cannot find protocol declaration when protocol is declared in its own .h file

Question

I created a protocol

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

// Defines the protocol that must be implemented to be a delegate for UCMapviewController
@protocol UCMapviewDelegate <NSObject>
@required
- (void)pushMapviewRight;

@end

When I go to new file -> protocol, there is a prompt which asks for the target. I check my project. But when i click the protocol.h file in my project and look at file inspector, at "Target membership", my project is unchecked and I cannot check it.

I don't get this error when I put the protocol in the header file of one of my viewControllers (for example). Do I have to import the protocol somewhere else?

WHat is wrong? Help is greatly appreciated! thx

stackoverflow.com/questions/7661334/…

jajo87
– jajo87

2012-05-10 00:15:22 +00:00
Commented May 10, 2012 at 0:15 — jajo87
– jajo87, Commented May 10, 2012 at 0:15

Lily Ballard · Accepted Answer · 2012-05-10 00:14:58Z

2

Header files don't go into a target, unless you're building a framework and want to copy the header file into the Headers folder in the framework. When building an app, only source files belong to the target.

You'll notice that if you select one of your other headers in your project, it will also not be in the target. Only the corresponding source file will be. This won't matter. If the header is in your project, you can #import it just fine.

answered May 10, 2012 at 0:14

Lily Ballard

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4 Comments

MJVDM Over a year ago

But if I import the protocol (if so, to the class that conforms to it ??), doesn't that defeat the purpose of it? I mean, my "AppDelegate" does not import UIApplicationDelegate.h ?!

Lily Ballard Over a year ago

@MJB: UIApplicationDelegate.h is certainly imported by your AppDelegate.m class, by virtue of importing <UIKit/UIKit.h>.

MJVDM Over a year ago

seems like I misunderstood that completely, thanks guys! So I do have to import the protocol.h in every file where I want to "use" it, be it an implementation or delegate property?

Lily Ballard Over a year ago

@MJB: No. The header for the class that declares conformance to the protocol should #import the protocol header, and now everything that touches that class will get it (since they'll already be #importing your class's header).

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