先写一个GCD
static UserInfoVoModel *userInfoShare = nil;
+(instancetype)shareUserInfoVoModel
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
userInfoShare = [[UserInfoVoModel alloc] init];
});
return userInfoShare;
}
原文：http://www.cnblogs.com/miaomiaocat/p/5377626.html