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 = 0;
    objc_property_t *properties = class_copyPropertyList([self class], &count);
    for (int i = 0; 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: 0)
        let buff = class_copyPropertyList(object_getClass(anyClass), count)
        let countInt = Int(count[0])
        
        for i in 0..<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 0..< 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, 0, 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：