单例模式Signaleton模式

对于单例模式刚开始挺陌生，到后来发现会挺好用，

static MyGizmoClass *sharedGizmoManager = nil;

 

+ (MyGizmoClass*)sharedManager

{

    if (sharedGizmoManager == nil) {

        sharedGizmoManager = [[super allocWithZone:NULL] init];

        }

    return sharedGizmoManager;

}

 

+ (id)allocWithZone: (NSZone *)zone

{

     return [[self sharedManager] retain];

}

 

- (id)copyWithZone: (NSZone *)zone

{

     return self ;

}

 

- (id)retain

{

     return self;

}

 

- (NSUInteger)retainCount

{

     return NSUIntegerMax;  //denotes an object that cannot be released

}

 

- (void)release

{

     //do nothing

}

 

- (id)autorelease

{

     return self;

}

如果需要修改里面的某属性时，只需调用修改就可