详解iOS App设计模式开发中对于享元模式的运用

- (NSInteger)getWebSiteCount;
 
@end
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#import "WebSiteFactory.h"
#import "ConcreteWebSite.h"
@implementation WebSiteFactory
 
- (instancetype)init {
    self = [super init];
    if (self) {
        _flyweights = [NSDictionary dictionary];
    }
    return self;
}
 
- (id<WebSiteProtocol>)getWebSiteCategory:(NSString *)webKey {    
    __block id<WebSiteProtocol> webset = nil;
    [self.flyweights enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        if (webKey == key) {
            webset = obj;
            *stop = YES;
        }
    }];
     
    if (webset == nil) {
        ConcreteWebSite *concreteWebset = [[ConcreteWebSite alloc] init];
        concreteWebset.webName = webKey;
        webset = concreteWebset;
         
        NSMutableDictionary *mutabledic = [NSMutableDictionary dictionaryWithDictionary:self.flyweights];
        [mutabledic setObject:webset forKey:webKey];
        self.flyweights = [NSDictionary dictionaryWithDictionary:mutabledic];
    }
     
    return webset;
}
 
- (NSInteger)getWebSiteCount {
    return self.flyweights.count;
}
 
@end
    代码中的getWebSiteCategory方法可以返回具体的享元对象，返回的这个享元对象同时遵守WebSiteProtocol的协议，WebSiteProtocol的代码如下：
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#import <Foundation/Foundation.h>
#import "User.h"
@protocol WebSiteProtocol <NSObject>
 
- (void)use:(User *)user;
 
@end
    ConcreteWebSite的代码如下：
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#import <Foundation/Foundation.h>
#import "WebSiteProtocol.h"
@interface ConcreteWebSite : NSObject <WebSiteProtocol>
 
@property (nonatomic, copy) NSString *webName;
 
@end