Objective-C Json转Model（利用Runtime特性）

Posted 2020-11-01 snail_1

封装initWithNSDictionary:方法

该方法接收NSDictionary对象, 返回PersonModel对象.

#pragma mark - 使用runtime将JSON转成Model

• (void)json2Model {
  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);
}
}

  使用runtime实现

  PersonModel的头文件如下:

  #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;

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

@end
实现文件:
#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

其中的代码也很简单:

使用class_copyPropertyList获取Model的所有属性列表, 遍历该列表使用property_getName即可得到所有属性名. 
对于PersonModel中定义的属性, 使用KVC即可将dict中的值赋给该属性.

转自:[id]:https://blog.csdn.net/icetime17/article/details/52040301