app crash on back button pressed

in my app i have 2 views

view1

{  
   [self.navigationController pushViewController:view2Controoler animated:YES];

}

view2

here when i am pressing back button app is crash without error or warning also in view2 i am using following code

paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);   
NSString *documentsDirectory = [paths objectAtIndex:0];  
NSFileManager *manager开发者_如何学Go = [NSFileManager defaultManager];  
NSArray *fileList = [manager directoryContentsAtPath:documentsDirectory ];  

in xcode last statement shows the warning "directoryContentsAtPath is depricated" so i try to use

NSArray *fileList = [manager directoryContentsAtPath:documentsDirectory error:NULL]; 

and this statement shows "NSFileManager may not respond to directoryContentsAtPath:error" anyways still I tried to run app and

app crashed with Exception "reason: '-[NSFileManager directoryContentsAtPath:error:]: unrecognized selector sent to instance 0x6302f50'"

I hope some one know how to solve this issue

Thank you

"

NSFileManager has no class methods other than +defaultManager. You should be using – contentsOfDirectoryAtPath:error: with your instance of a file manager.

I think directoryContentsAtPath: returns an autoreleased object.

If you have directoryContent set up as a @property(nonatomic, retain) in your header you can set it using

self.directoryContent = [[NSFileManager defaultManager] directoryContentsAtPath: documentsDirectory];

and it will automatically retain the object returned by NSFileManager, otherwise you could call

directoryContent = [[[NSFileManager defaultManager] directoryContentsAtPath: documentsDirectory] retain];

but be sure to release that object when you no longer need it.

From Apple Documentation

directoryContentsAtPath:
Returns the directories and files (including symbolic links) contained in a given directory. (Deprecated in iOS 2.0. Use contentsOfDirectoryAtPath:error: instead.)

- (NSArray *)directoryContentsAtPath:(NSString *)path

From Apple Documentation Suggest you to use

- (NSArray *)contentsOfDirectoryAtPath:(NSString *)path error:(NSError **)error