OC高效率52之經過協議提供匿名對象

#import <Foundation/Foundation.h>
@protocol EOCDatabaseConnection
-(void)connect;
-(void)disconnect;
-(BOOL)isConnected;
-(NSArray*)performQuery:(NSString*)query;
@end

/**
 *  能夠用協議把本身所寫的API之中的實現細節隱藏起來，將返回的對象設計爲聽從此協議的純id類型，想要隱藏的類名就不會出如今API中了
 */
@interface EOCDatabaseManager : NSObject
+(id)sharedInstance;
-(id<EOCDatabaseConnection>)connectionWithIdentifier:(NSString *)identifier;
@end


@implementation EOCDatabaseManager

@end