isKindOfClass doesn't work as expected

问题

i'm working on a iOS5+ project (xcode 4.4.1 SDK 5.1)

i have this code inside a unit test:

[_appDelegate application:nil didFinishLaunchingWithOptions:nil];

UITabBarController *tabBarController = (UITabBarController*)_appDelegate.window.rootViewController;

NSArray *viewControllers = [tabBarController viewControllers];

UINavigationController *nc_1 = [viewControllers objectAtIndex:0];
UIViewController *vc_1 = nc_1.topViewController;

STAssertTrue([vc_1 isKindOfClass:[ScheduleViewController class]]==YES, @"UITabBarController first tab should be a ScheduleViewController class");

If i run the test, the test fail.

So i check with the debugger:

(lldb) po [ScheduleViewController class]
(id) $1 = 0x00142b04 ScheduleViewController
(lldb) po vc_1
(UIViewController *) $2 = 0x11a32dc0 <ScheduleViewController: 0x11a32dc0>
(lldb) print (BOOL) [vc_1 isKindOfClass:(Class)[ScheduleViewController class]]
(BOOL) $4 = YES
(lldb) po [vc_1 class]
(id) $5 = 0x00142b04 ScheduleViewController
(lldb) 

In application:didFinishLaunchingWithOptions: i create a ScheduleViewController and i use it as rootController of the navigation controller. The debugger say it's correct. I don't understand what is wrong with the assert above.

Someone have idea about this?

Update

The first implementation of thE assert was:

STAssertTrue([vc_1 isKindOfClass:[ScheduleViewController class]], @"UITabBarController first tab should be a ScheduleViewController class");

The assert failed at the same way.

Update 2

As suggested in the comment i try to add this piece of code before the assert:

BOOL vcBool = [vc_1 isKindOfClass:[ScheduleViewController class]];

With the debugger i see:

(lldb) print (BOOL) [vc_1 isKindOfClass:(Class)[ScheduleViewController class]]
(BOOL) $1 = YES
(lldb) print (BOOL) vcBool
(BOOL) $2 = NO
(lldb) 

Update 3

I added this line, as suggested in the comments, before the assert:

NSLog(@"vc_1=%@ class=%@", vc_1, NSStringFromClass([vc_1 class]));

From the debug console:

vc_1=<ScheduleViewController: 0x993bdb0> class=ScheduleViewController

回答1:

I found the solution.

It's the inverse of the solution presented in the post linked by @vacawama in the comments. I had all *.m source of the app target in the test target too. While i was searching for a solution to the isKindOfClass problem i noticed a lot of warning on the console at the begin of the test session. The warnings was like this:

Class AClass is implemented in both /Application Support/iPhone Simulator/5.0/Applications/7FC68A9C-4F2C-4A30-85AD-87D8ABA7A275/App.app/App and /Developer/Xcode/DerivedData/App-fvbgaqbdupuoodgquxhlwbudpsin/Build/Products/Debug-iphonesimulator/App.octest/AppTests. One of the two will be used. Which one is undefined.

I removed all .m files of the application from test target.

Now isKindOfClass works as expected.

Thank to all for the support.

回答2:

You shouldn't directly compare BOOL values to YES. It's possible this is causing the issue with your assert. Here's a reference with background on the issue: http://mobiledevelopertips.com/objective-c/of-bool-and-yes.html

回答3:

Converting a class name to string with NSStringFromClass will avoid problems with isKindOfClass... example:

if ([NSStringFromClass([AViewController class]) isEqualToString:NSStringFromClass([BViewController class])])

来源：https://stackoverflow.com/questions/12386189/iskindofclass-doesnt-work-as-expected