特别注意的是这个只能是字典，在model层中定义json数据中你需要的属性就好，但是属性名必须和json中的属性名（key）相同###

</br>

程序的入口是调用这个方法####

-  (void)jsonWithSetAttributeForModelFromDictionnary: (NSDictionary *) dictionnaryOfJson

**建立映射关系：json数据中的key为关键字就改成类名+关键字,
如json数据中 key = id 那么model中设置属性不可能用model.id调用吧；所以改为类名+ID这样就能调用了 **
- (NSMutableDictionary *)relationShipBetweenModelAndJson:(NSDictionary *)dic {

       //取出字典中所有的key
       NSArray *keys = [dic allKeys];

      NSMutableDictionary *newDic = [NSMutableDictionary dictionary];
/*
 1.产生映射关系如title的set方法---->setTitle
 2.创建一个可变字典将key(本身) ：value(本身)如果为传过来的字典中有关键字则value变成类名加本身。如id ---->NSStringFromClass+id
 3.返回
 
 */

for (NSString *keyStr in keys) {
    
    
    if ([keyStr isEqualToString:@"id"]) {
        
        NSString *classStr = NSStringFromClass([self class]);
        NSString *newStr = [NSString stringWithFormat:@"%@Id",classStr];
        [newDic setObject:newStr forKey:@"id"];
    
    }
    
    else if ([keyStr isEqualToString:@"release"]){
        NSString *classStr = NSStringFromClass([self class]);
        NSString *newStr = [NSString stringWithFormat:@"%@Release",classStr];
        [newDic setObject:newStr forKey:@"release"];
      
    }
    else {
    
        [newDic setObject:keyStr forKey:keyStr];
    
    }
    
}
 return newDic;
}

**映射好属性后可以为每个属性生成set方法
如：name ----------->setName: **
- (SEL)createSetMethodForValue :(NSString *)KeyName {

   //截取第一个单词并大写
     NSString *fisrtWord = [[KeyName substringToIndex:1]uppercaseString];

   //截取剩余的字符
     NSString *otherStr = [KeyName substringFromIndex:1];

   //拼接
     NSString *setterStr = [NSString stringWithFormat:@"set%@%@:",fisrtWord,otherStr];

   //构建set方法
    SEL setterMethod = NSSelectorFromString(setterStr);

     return setterMethod;

}

将json数据中的value取出来然后为每个set方法赋值
- (void)jsonWithSetAttributeForModelFromDictionnary: (NSDictionary *) dictionnaryOfJson{

//获取构建好的映射字典
NSMutableDictionary *mDictionary = [self relationShipBetweenModelAndJson:dictionnaryOfJson];

NSArray *allKey = [mDictionary allKeys];

for (NSString *key in allKey) {
    
    //获取新构建的key
    NSString *popertyName = [mDictionary objectForKey:key];
    
    //根据新构建的key建立set方法 如：rating--->setRating
    SEL method = [self createSetMethodForValue:popertyName];
    
    //获取原有字典中key的值
    id value = [dictionnaryOfJson objectForKey:key];
    
    //判断你在model中有没有设置这个属性，如果没有设置这个属性就不执行下面的方法
    if ([self respondsToSelector:method]) {
         
        //这里是为set方法赋值
        [self performSelector:method withObject:value];
        }
     }
}