Is very easy, you only have to use this method:

 

– (NSDictionary *) indexKeyedDictionaryFromArray:(NSArray *)array

{

id objectInstance;

NSUInteger indexKey = 0;

NSMutableDictionary *mutableDictionary = [[NSMutableDictionary alloc] init];

for (objectInstance in array)

[mutableDictionary setObject:objectInstance forKey:[NSNumber numberWithUnsignedInt:indexKey++]];

return (NSDictionary *)[mutableDictionary autorelease];

}