NSMutableDictionary中不区分大小写的搜索

@interface NSDictionary (caseINsensitive)
-(id) objectForCaseInsensitiveKey:(id)aKey;
@end


@interface NSMutableDictionary (caseINsensitive)
-(void) setObject:(id) obj forCaseInsensitiveKey:(id)aKey ;
@end


@implementation NSDictionary (caseINsensitive)

-(id) objectForCaseInsensitiveKey:(id)aKey {
    for (NSString *key in self.allKeys) {
        if ([key compare:aKey options:NSCaseInsensitiveSearch] == NSOrderedSame) {
            return [self objectForKey:key];
        }
    }
    return  nil;
}
@end


@implementation NSMutableDictionary (caseINsensitive)

-(void) setObject:(id) obj forCaseInsensitiveKey:(id)aKey {
    for (NSString *key in self.allKeys) {
        if ([key compare:aKey options:NSCaseInsensitiveSearch] == NSOrderedSame) {
            [self setObject:obj forKey:key];
            return;
        }
    }
    [self setObject:obj forKey:aKey];
}

@end

__block id object;
[dictionary enumerateKeysAndObjectsWithOptions:NSEnumerationConcurrent 
                                    UsingBlock:^(id key, id obj, BOOL *stop){
    if ( [key isKindOfClass:[NSString class]] ) {
        if ( [(NSString*)key caseInsensitiveCompare:aString] == NSOrderedSame ) {
            object = obj; // retain if wish to.
            *stop = YES;
        }            
    }
}];

#define

NSMutableDictionary

objectForKey

setObject:ForKey

@Interface CaseInsensitveMutableDictionary : MutableDictionary {}
@end

@implementation CaseInsensitveMutableDictionary
    - (void) setObject: (id) anObject forKey: (id) aKey {
       [super setObject:anObject forKey:[skey lowercaseString]];
    }

    - (id) objectForKey: (id) aKey {
       return [super objectForKey: [aKey lowercaseString]];
    }
@end