1.message.txt
[ {
"sender":"小花",
"receiver":"小新",
"content":"向日葵的微笑永远只为太阳而笑",
"data":"2017年6月1日"
},{
"sender":"小花",
"receiver":"小新",
"content":"万丈高楼平地起",
"data":"2017年6月2日"
}]

2.Message.h
@interface Message : NSObject
@property(nonatomic,copy)NSString * sender;
@property(nonatomic,copy)NSString * receiver;
@property(nonatomic,copy)NSString * content;
@property(nonatomic,copy)NSString * data;
3.Message.m
//防崩
-(void)setValue:(id)value forUndefinedKey:(NSString *)key{

}
4.ViewController.m

import "ViewController.h"

import "Message.h"

import "JSONKit.h"

@interface ViewController ()

• (IBAction)jsonKit:(UIButton *)sender;
  //存储模型对象:
  @property(nonatomic,strong)NSMutableArray * dataArray;
  @end

• (IBAction)jsonKit:(UIButton *)sender {
  //获取文件路径
  NSString * filepath = [[NSBundle mainBundle]pathForResource:@"message.txt" ofType:nil ];
  //2.转换放入数据
  NSData * fileData = [NSData dataWithContentsOfFile:filepath];
  NSArray * tempArray = [fileData objectFromJSONData];
  NSLog(@"%@",tempArray);
  //3.初始化数组,再用来接收模型对象
  self.dataArray = [NSMutableArray array];
  //遍历数组，取出字典，然后通过KVC将字典当中元素取出，放入 self.dataArray中
  for (NSDictionary * dict in tempArray) {
  // 创建模型对象
  Message * message = [Message new];
  //通过KVC将字典转化为模型对象
  [message setValuesForKeysWithDictionary:dict];
  [self.dataArray addObject:message];
  }
  //测试
  [self.dataArray enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
  NSLog(@"%@ %@ %@ %@",[obj sender],[obj receiver],[obj content],[obj data]);
  }];

}