（objective-c 自定义 NSDictionary 键类的注意事项）工程

// // KeyObject.h // DictionaryKeyObject // // Created by BruceYang on 12-7-29. // Copyright (c) 2012年 EricGameStudio. All rights reserved. // #import <Foundation/Foundation.h> @interface KeyObject : NSObject { int _x; int _y; } @property int x; @property int y; +(id) kObjectWithX:(int)x y:(int)y; -(id) initWithX:(int)x y:(int)y; -(id) copyWithZone:(NSZone*)zone; -(NSString*) description; -(NSUInteger) hash; -(BOOL) isEqual:(id)object; @end