各种对象转为json字符串

//对象转化为字典

-(NSMutableDictionary *)onereturnToDictionaryWithModel:(ScorelistTwo *)model

{

    NSMutableDictionary *userDic = [NSMutableDictionary dictionary];

    unsigned int count = 0;

    objc_property_t *properties = class_copyPropertyList([ScorelistTwo class], &count);

    for (int i = 0; i < count; i++) {

        const char *name = property_getName(properties[i]);

        NSString *propertyName = [NSString stringWithUTF8String:name];

        id propertyValue = [model valueForKey:propertyName];

        if (propertyValue) {

            [userDic setObject:propertyValue forKey:propertyName];

        }

    }

    free(properties);

    return userDic;

}