使用OC进行Json解析--JsonModel

直入主题，如何解析复杂的Json数据？所谓的复杂的Json数据是指三层及以上的带数组的嵌套模型。如下展示的是一个较复杂的Json字符串--最外层是一个字典，字典里面有一个数组，数组里面是一个字典，字典里面是第二层数组，这第二层数组里面还有一个字典。

{"code":1,"msg":"获取数据成功","data":[{"content":[{"content":[{"id":1,"identity_label":"施工员1","style":"","icon":""},{"id":2,"identity_label":"施工员2","style":"","icon":""}],"name":"管理人员","labels_class":1},{"content":[{"id":3,"identity_label":"水泥工","style":"","icon":""},{"id":4,"identity_label":"木工","style":"","icon":""}],"name":"技术工人","labels_class":2},{"content":[{"id":5,"identity_label":"泥工班组","style":"","icon":""},{"id":6,"identity_label":"木工班组","style":"","icon":""}],"name":"施工班组","labels_class":3}],"labels_type":1,"labels_name":"工人"},{"content":[{"content":[{"id":7,"identity_label":"60小型挖机","style":"","icon":""},{"id":8,"identity_label":"起重机","style":"","icon":""},{"id":9,"identity_label":"挖土机","style":"","icon":""}],"name":"机械设备","labels_class":4}],"labels_type":2,"labels_name":"机械"},{"content":[{"content":[{"id":10,"identity_label":"水泥","style":"","icon":""},{"id":11,"identity_label":"钢筋","style":"","icon":""},{"id":12,"identity_label":"沙子","style":"","icon":""}],"name":"材料","labels_class":5}],"labels_type":3,"labels_name":"材料商"},{"content":[{"content":[{"id":13,"identity_label":"土建","style":"","icon":""},{"id":14,"identity_label":"市政","style":"","icon":""},{"id":15,"identity_label":"幕墙门窗","style":"","icon":""}],"name":"专业分包","labels_class":6}],"labels_type":4,"labels_name":"包工"},{"content":[{"content":[{"id":16,"identity_label":"房建工程","style":"","icon":""},{"id":17,"identity_label":"装饰工程","style":"","icon":""},{"id":18,"identity_label":"道路工程","style":"","icon":""}],"name":"工程项目","labels_class":7}],"labels_type":5,"labels_name":"项目"}]}

1、首先看最外层的字典，有三个键：code、msg、data，分别对应数字类型、字符串类型、数组类型，数字类型可以用NSInteger、CGFloat、NSNumber来接收（注：如果数字类型的关键字是id，不要使用NSNumber接收），字符串就用NSString接收，具体操作如下：

@property (nonatomic) NSNumber *code;
@property (nonatomic) NSString *msg;

//接收关键字为id的数字类型
@property (nonatomic) NSInteger id;

重点讲一下接收数组类型,先上代码

#import "BaseModel.h"//继承自BaseModel
#import "IDTagClassModel.h"//引用数组中模型
//声明一个协议，注意这个协议是必须要的，不然没办法嵌套
@protocol IDTagClassModel <NSObject>
@end

@interface IDTagRootModel : BaseModel
//与协议相互配合，就知道了数组里面放的是一个模型了
@property (nonatomic) NSArray<IDTagClassModel> *data;
@property (nonatomic) NSNumber *code;
@property (nonatomic) NSString *msg;

@end

接下来的操作就是重复上述过程了。

将数据模型建立好之后，就是解析了：

NSError *error;
//当最外层是数组时：
NSArray *arr = [IDTagRootModel arrayOfModelsFromData:data error:&error];
//当最外层是字典的时候：
IDTagDetailModel *model = [IDTagDetailModel dictionaryOfModelsFromDictionary:dic error:error];

if (!error) {
    //解析成功
 }

平时最常用的就是数组转模型了，当然还有data转模型、模型转data，主要用于模型的存储。