// .h文件
#import <Foundation/Foundation.h>@interface NSCodingProtocolHelper : NSObject+(void)encodeWithCoder:(NSCoder *)aCoder andObj:(id)obj;+(id)initWithCoder:(NSCoder *)aDecoder andObj:(id)obj;@end

// .m文件
#import "NSCodingProtocolHelper.h"#import <objc/runtime.h> //反射需要用到的头文件@implementation NSCodingProtocolHelper+(void)encodeWithCoder:(NSCoder *)aCoder andObj:(id)obj{    unsigned int outCount;    objc_property_t *properties = class_copyPropertyList([obj class], &outCount);    for (int i = 0; i < outCount; i++) {        objc_property_t *thisProperty = properties + i;        NSString *propertyName = [NSString stringWithUTF8String:property_getName(*thisProperty)];        [aCoder encodeObject:[obj valueForKey:propertyName] forKey:propertyName];    }}+(id)initWithCoder:(NSCoder *)aDecoder andObj:(id)obj{    unsigned int outCount;    objc_property_t *properties = class_copyPropertyList([obj class], &outCount);    for (int i = 0; i < outCount; i++) {        objc_property_t *thisProperty = properties + i;        NSString *propertyName = [NSString stringWithUTF8String:property_getName(*thisProperty)];        [obj setValue:[aDecoder decodeObjectForKey:propertyName] forKey:propertyName];    }    return obj;}@end

-(void) encodeWithCoder:(NSCoder *)aCoder{    [NSCodingProtocolHelper encodeWithCoder:aCoder andObj:self];    }-(id)initWithCoder:(NSCoder *)aDecoder{    return [NSCodingProtocolHelper initWithCoder:aDecoder andObj:selfl];}