简单实现MJExtension(一) -- 字典转模型

三、字典数组 to 模型

#pragma mark - 复杂字典 转 模型
- (void)keyValuesArrayToObject {

    // 1.定义一个字典数组
    NSArray *dictArray = @[
                           @{
                               @"name" : @"Jack",
                               @"icon" : @"lufy.png",
                               },

                           @{
                               @"name" : @"Rose",
                               @"icon" : @"nami.png",
                               }
                           ];
}

在 NSObject+Extension.m 文件中添加方法+ objectArrayFromKeyValuesArray:

+ (NSMutableArray *)objectArrayFromKeyValuesArray:(NSArray *)keyValuesArray {

    // 1.创建数组
    NSMutableArray *modelArray = [NSMutableArray array];

    // 2.遍历传进来的字典数组
    for (NSDictionary *keyValues in keyValuesArray) {
        if ([keyValues isKindOfClass:[NSArray class]]) {

            [modelArray addObject:[self objectArrayFromKeyValuesArray:(NSArray *)keyValues]];
        }
        else {
            id model = [self objectFromKeyValue:keyValues];
            if (model) {
                [modelArray addObject:model];
            }
        }
    }
    return modelArray;
}

回到ViewController 在字典数组下面

NSArray *modelArr = [YLUserModel objectArrayFromKeyValuesArray:dictArray];

    for (YLUserModel *user in modelArr) {
        NSLog(@"name = %@",user.name);
    }

字典数组 to 模型 的输出.png

四、用自定义的属性名接收key

#pragma mark - 用自定义的属性名接收key
- (void)keyValuesArrayToObjectReplace {

    // 1.定义一个字典
    NSDictionary *dict = @{
                           @"id" : @"20",
                           @"desciption" : @"好孩子",
                           @"name" : @"Jack",
                           };
}

// 在模型里实现协议
+ (NSDictionary *)replacedKeyFromPropertyName {

    return @{
             @"ID" : @"id",
             @"desc" : @"desciption"
             };
}

修改 + objectFromKeyValue: 方法

+ (instancetype)objectFromKeyValue:(NSDictionary*)keyValue {

    id obj = [[self alloc]init];

    unsigned int count;

    // 获取成员变量数组:注意:只会获取当前类的属性,不会获取父类
    Ivar *ivarList = class_copyIvarList(self, &count);

    // 遍历
    for (int i = 0; i < count; i++) {
        Ivar ivar = ivarList[i];
        // 获取成员变量名字
        NSString *ivarName = [NSString stringWithUTF8String:ivar_getName(ivar)];
        //NSLog(@"ivarName = %@",ivarName);//_age _name _icon _height _money

        // 截取 - 获得模型的属性名
        NSString *modelProperty = [ivarName substringFromIndex:1];
        //NSLog(@"modelProperty = %@",key);//age name icon height money

        NSString *keyBeReplaced; // 判断是否要被替换 不判断会死
        if ([self respondsToSelector:@selector(replacedKeyFromPropertyName)]) {
            keyBeReplaced = [self replacedKeyFromPropertyName][modelProperty];
        }

        // 获取字典里的值 (判断是否是被替换的)
        id value;
        if (keyBeReplaced) {

            value = keyValue[keyBeReplaced];
        }
        else{

            value = keyValue[modelProperty];
        }

        // 复杂字典,里面还有字典
        // 所以要获取成员变量的类型
        NSString *ivarType = [NSString stringWithUTF8String:ivar_getTypeEncoding(ivar)];
        // @\"YLUserModel\" 需要截取 ,否则下面的 secIvarClass 是不存在的(这里要好好看下MJExtension,这个解决方式比较low)
        ivarType = [ivarType stringByReplacingOccurrencesOfString:@"@" withString:@""];
        ivarType = [ivarType stringByReplacingOccurrencesOfString:@"\"" withString:@""];
        //NSLog(@"ivarType = %@",ivarType);
        if ([value isKindOfClass:[NSDictionary class]] && ![ivarType hasPrefix:@"NS"]) {

            Class secIvarClass = NSClassFromString(ivarType);
            value = [secIvarClass objectFromKeyValue:value];
            NSLog(@"");
        }

        // 赋值
        [obj setValue:value forKey:modelProperty];
    }

    return obj;
}

回到ViewController 在字典下面

    YLUserModel *user = [YLUserModel objectFromKeyValue:dict];

    NSLog(@"name = %@,ID = %@,desc = %@",user.name,user.ID,user.desc);

用自定义的属性名接收key 的输出.png

今天到此结束,下次的是字典里有数组,数组里又有字典的情况