单例设计模式IOS

#import "ZBAccountInfo.h"

@interface ZBAccountInfo()

@end

static ZBAccountInfo *sharedObj = nil;

@implementation ZBAccountInfo

+(ZBAccountInfo *)sharedInstance{

@synchronized (self)

{

if (sharedObj == nil)

{

sharedObj=  [[self alloc] init];

}

}

return sharedObj;

}

+(id)allocWithZone:(struct _NSZone *)zone{

@synchronized (self) {

if (sharedObj == nil) {

sharedObj = [super allocWithZone:zone];

return sharedObj;

}

}

return sharedObj;

}

@end