模型对象深复制，new 一个新的模型对象，将旧模型的各个属性值全部赋值过去

#import <objc/runtime.h>

#pragma mark 模型拷贝  在<YYModel>时会多出4个私有属性
//hash  superclass  description  debugDescription
+(id)changeModle:(id)model modelClassname:(NSString *)classname
{
    return [self changeModle:model modelClassname:classname removeKey:nil];
}

#pragma mark 模型拷贝  在<YYModel>时会多出4个私有属性
//hash  superclass  description  debugDescription
//rKey 排除某个key
+(id)changeModle:(id)model modelClassname:(NSString *)classname removeKey:(NSArray *)rKeyArray
{
    unsigned int count;
    objc_property_t *properties=class_copyPropertyList([model class], &count);
    
    /*
     unsigned int ivarCount;
     Ivar *ivars = class_copyIvarList([model class], &ivarCount);
     */
    id backModel=[[NSClassFromString(classname) alloc]init];
    
    unsigned int count_new;
    objc_property_t *properties_new = class_copyPropertyList([backModel class], &count_new);
    
    //    if (count > count_new) {
    //        count = count_new;
    //    }
    
    for(int i =0; i < count; i++) {
        objc_property_t property = properties[i];
        //获取属性的名称C语言字符串
        const char *cName = property_getName(property);
        //转换为Objective C字符串
        NSString *name = [NSString stringWithCString:cName encoding:NSUTF8StringEncoding];
        
        
        //去掉私有属性
        //方法一
        if ([name isEqualToString:@"hash"] || [name isEqualToString:@"superclass"] || [name isEqualToString:@"description"] || [name isEqualToString:@"debugDescription"]) {
            continue;
        }
        
        /*
         //方法二  错误 不可以，属性前有 _(eg:_id)
         BOOL flag = YES;
         for (int j = 0; j < ivarCount; ++j) {
         const char *iName = ivar_getName(ivars[j]);
         NSString *_name = [NSString stringWithUTF8String:iName];
         if ([_name isEqualToString:name]) {
         break;
         }else{
         if (j == ivarCount - 1) {
         flag = NO;
         }
         }
         }
         if (!flag) {
         continue;
         }
         */
        
        
        id value= [model valueForKey:name];
        if (![value isKindOfClass:[NSNull class]] && value != nil) {
            //            [backModel setValue:value forKey:name];
            
            for (int j = 0; j < count_new; ++j) {
                
                objc_property_t property_new = properties_new[j];
                //获取属性的名称C语言字符串
                const char *cName_new = property_getName(property_new);
                //转换为Objective C字符串
                NSString *name_new = [NSString stringWithCString:cName_new encoding:NSUTF8StringEncoding];
                if ([rKeyArray containsObject:name]) {
                    continue;
                }
                if ([name isEqualToString:name_new]) {
                    //保证对相同属性赋值
                    [backModel setValue:value forKey:name];
                    break;
                }
                
            }
            
        }
        
    }
    free(properties_new);
    free(properties);
    return backModel;
}
//移除模型某个属性值 注意modelCustomPropertyMapper, 解决key转换
/*
 + (NSDictionary<NSString *,id> *)modelCustomPropertyMapper{
 return @{@"nVer":@"newVer"};
 }
 */
+(id)changeModel:(id)model removeKey:(NSArray *)rKeyArray modelCustomPropertyMapper:(NSDictionary *)mDic{
    
    unsigned int count;
    objc_property_t *properties=class_copyPropertyList([model class], &count);
    
//    id backModel=[[NSClassFromString(NSStringFromClass([model class])) alloc]init];
    id backModel = [NSMutableDictionary dictionary];
    for(int i =0; i < count; i++) {
        objc_property_t property = properties[i];
        //获取属性的名称C语言字符串
        const char *cName = property_getName(property);
        //转换为Objective C字符串
        NSString *name = [NSString stringWithCString:cName encoding:NSUTF8StringEncoding];
        //去掉私有属性
        //方法一
        if ([name isEqualToString:@"hash"] || [name isEqualToString:@"superclass"] || [name isEqualToString:@"description"] || [name isEqualToString:@"debugDescription"]) {
            continue;
        }
        id value= [model valueForKey:name];
        if (![value isKindOfClass:[NSNull class]] && value != nil) {
            if ([rKeyArray containsObject:name]) {
                continue;
            }
            NSString *mName = [mDic valueForKey:name];
            if (mName) {
                name = mName;
            }
            [backModel setValue:value forKey:name];
        }
    }
    free(properties);
    return backModel;
}

ps: YYModel 中也提供模型复制的方法