//下面这段宏考过去直接用#define SYNTHESIZE_SINGLETON_FOR_HEADER(className) \+ (className *)sharedInstance;
+ (void)destroyInstance;
//在单例生成之前onceToken = 0,在单例生成之后onceToken = -1了,之后一直保持-1这个值,知道这个之后我想你应该有思路了#define SYNTHESIZE_SINGLETON_FOR_CLASS(className) \static className *shared##className = nil;
static dispatch_once_t onceToken;
+ (className *)sharedInstance{
return [[self alloc] init];
}
+ (className *)allocWithZone:(struct _NSZone *)zone{
dispatch_once(&onceToken, ^{
shared##className = [super allocWithZone:zone];
}
);
return shared##className;
}
- (className *)copyWithZone:(NSZone *)zone{
return shared##className;
}
- (className *)mutableCopyWithZone:(NSZone *)zone{
return shared##className;
}
+ (void)destroyInstance {
shared##className = nil;
onceToken = 0;
}

//用法，注意要遵循NSCopying,NSMutableCopying 协议import <Foundation/Foundation.h>@interface YNHTUserModel : NSObject<NSCopying,NSMutableCopying>SYNTHESIZE_SINGLETON_FOR_HEADER(YNHTUserModel);
@property (nonatomic,copy) NSString* inviter_id;
//邀请人ID@property (nonatomic,copy) NSString* token;
@property (nonatomic,copy) NSString* nick_name;
@end

#import "YNHTUserModel.h"@implementation YNHTUserModelSYNTHESIZE_SINGLETON_FOR_CLASS(YNHTUserModel);
@end