反射--> 解析JSON数据

方法一

Persons.json文件

[
 {
 "name": "Chris",
 "age": 18,
 "city": "Shanghai",
 "job": "iOS"
 },
 {
 "name": "Ada",
 "age": 16,
 "city": "Beijing",
 "job": "student"
 },
 {
 "name": "Rita",
 "age": 17,
 "city": "Xiamen",
 "job": "HR"
 }
 ]

Model.h类

 #import <Foundation/Foundation.h>

 @interface PersonModel : NSObject

 @property (nonatomic, copy) NSString *name;
 @property (nonatomic, assign) NSInteger age;
 @property (nonatomic, copy) NSString *city;
 @property (nonatomic, copy) NSString *job;
 @property (nonatomic, copy) NSString *sex;

 - (instancetype)initWithNSDictionary:(NSDictionary *)dict;

 @end

Model.m类

 #import "PersonModel.h"
 #import <objc/runtime.h>

 @implementation PersonModel

 - (instancetype)initWithNSDictionary:(NSDictionary *)dict {
     self = [super init];
     if (self) {
         [self prepareModel:dict];
     }
     return self;
 }

 - (void)prepareModel:(NSDictionary *)dict {
     NSMutableArray *keys = [[NSMutableArray alloc] init];

     u_int count = ;
     objc_property_t *properties = class_copyPropertyList([self class], &count);
     for (int i = ; i < count; i++) {
         objc_property_t property = properties[i];
         const char *propertyCString = property_getName(property);
         NSString *propertyName = [NSString stringWithCString:propertyCString encoding:NSUTF8StringEncoding];
         [keys addObject:propertyName];
     }
     free(properties);

     for (NSString *key in keys) {
         if ([dict valueForKey:key]) {
             [self setValue:[dict valueForKey:key] forKey:key];
         }
     }
 }

 @end

调用

 NSString *file = [[NSBundle mainBundle] pathForResource:@"Persons" ofType:@"json"];
     NSData *data = [NSData dataWithContentsOfFile:file];
     NSMutableArray *array = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];

     for (NSDictionary *model in array) {
         PersonModel *person = [[PersonModel alloc] initWithNSDictionary:model];
         NSLog(@"%@, %ld, %@, %@", person.name, (long)person.age, person.city, person.job);
     }

打印结果：

---

方法二

数据模型的父类是：JSONModel

JSONModel的子类是：JSONPerson， JSONStudent， JSONTeacther等；

JSONStudent.h中

 @import JSONModel;

 @interface JSONStudent : JSONModel

 @property (nonatomic, copy) NSString * id;
 @property (nonatomic, copy) NSString * name;
 @property (nonatomic, copy) NSString * nickName;
 @property (nonatomic, copy) NSString * phoneNumber;

 @end

注意：这是用OC来写的！

获取属性

 func getAllProperties<T: JSONModel>(anyClass: T) -> [String] {
         var properties = [String]()
         let count = UnsafeMutablePointer<UInt32>.allocate(capacity: )
         let buff = class_copyPropertyList(object_getClass(anyClass), count)
         let countInt = Int(count[])

         for i in ..<countInt {
             let temp = buff![i]
             let tempPro = property_getName(temp)
             let proper = String(utf8String: tempPro!)
             properties.append(proper!)
         }
         return properties

     }

注意：获取属性使用Swift写的，单纯用Swift和OC要简单！

使用

 func returnListStudent(students: [JSONStudent]) {
         for item in students {
             let studentProperties = self.getAllProperties(anyClass: item)
             for i in ..< studentProperties.count{
                 print("值是：\(item.value(forKey: studentProperties[I]))" + "属性是：\(studentProperties[i])"self.dataError)
             }
         }
     }

方法三

User.swift

 import UIKit

 class User: NSObject {
     var name:String = ""  //姓名
     var nickname:String?  //昵称
     var age:Int?   //年龄
     var emails:[String]?  //邮件地址
 }

Mirror

属性

//    实例化
let user = User()
let mirror: Mirror = Mirror(reflecting:user)

//    subjectType：对象类型

print(mirror.subjectType) // 打印出：User

//    children：反射对象的属性集合

//    displayStyle：反射对象展示类型

// advance 的使用
let children = mirror.children
let p0 = advance(children.startIndex, , children.endIndex) // name 的位置
let p0Mirror =  Mirror(reflecting: children[p0].value) // name 的反射
print(p0Mirror.subjectType) //Optional<String> 这个就是name 的类型

调用：

     @objc func testOne() {
 //        得到应用名称
         let nameSpace = Bundle.main.object(forInfoDictionaryKey: "CFBundleName") as! String
         let clsName = "User"
 //        使用NSClassFromString通过类名得到实例(得到类的完整路径， 注意分隔符是小数点；并判断数据类型是否符合预期。 备注： as？后面的格式是类名.Type， cls可能是nil)
         guard let cls = NSClassFromString(nameSpace + "." + clsName) as? NSObject.Type else { return }  //得到类完整路径
         print("------_>\(cls)")
         let user = cls.init()
         print("------111111_>\(user)")

 //        使用Mirror得到属性值
         let mirror = Mirror(reflecting: user)
         for case let(key?, value) in mirror.children {
             print("key:\(key), value: \(value)")    //打印成员属性
         }
         print(mirror.subjectType)    //反射对象的数据类型</span>

     }

打印：