在IOS中使用json

1、从https://github.com/stig/json-framework/中下载json框架：json-framework

2、解压下载的包，将class文件夹下的所有文件导入到当前工程下。

3、在使用的文件中加入导入语句 ：#import "SBJson.h"

4、将json字符串转为NSDictionary对象。

       

NSString *temp=@"{"中国":{
                          "北京":{"北京1":1,"北京2":2,"北京3":3},
                         "上海":{"上海1":4,"上海2":5,"上海3":6},
                         "广州":{"广州1":7,"广州2":8,"广州3":9}}}";
NSDictionary *items = [temp JSONValue];

 NSString *temp=@"{"中国":{
                           "北京":{"北京1":1,"北京2":2,"北京3":3},
                          "上海":{"上海1":4,"上海2":5,"上海3":6},
                          "广州":{"广州1":7,"广州2":8,"广州3":9}}}";
 NSDictionary *items = [temp JSONValue];

 5、递归遍历解析出的NSDictionary对象

-(void)visitDict:(NSDictionary *)dict{
  NSArray *keys=[dict allKeys];
  for (NSString *key in keys) {
     NSString *result=[NSString stringWithFormat:@"key=%@,value=%@",key,[dict objectForKey:key]];
     NSLog(result);
     if([[dict objectForKey:key] isKindOfClass:[NSDictionary class]]){
            [self visitDict:[dict objectForKey:key]];
     }
   }
}

-(void)visitDict:(NSDictionary *)dict{
  NSArray *keys=[dict allKeys];
  for (NSString *key in keys) {
     NSString *result=[NSString stringWithFormat:@"key=%@,value=%@",key,[dict objectForKey:key]];
     NSLog(result);
     if([[dict objectForKey:key] isKindOfClass:[NSDictionary class]]){
            [self visitDict:[dict objectForKey:key]];
     }
   }
}

 6、将解析出的NSDictionary对象还原为json字符串

                

NSString * jsonStr=[items JSONRepresentation];

NSString * jsonStr=[items JSONRepresentation];