ios 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。
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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

[cpp]  view plain copy

//测试json的解析  
-(void)testJsonParser: (NSString *) jsonString  
{  
    jsonString = [[NSString alloc] initWithString:@"{\"userInfo\":{\"userName\":\"张三\",\"sex\":\"男\"}}"];  
    NSLog(@"正在解析json字符串是：%@",jsonString);  
      
    SBJsonParser * parser = [[SBJsonParser alloc] init];  
    NSError * error = nil;  
    NSMutableDictionary *jsonDic = [parser objectWithString:jsonString error:&error];  
    NSMutableDictionary * dicUserInfo = [jsonDic objectForKey:@"userInfo"];  
      
    NSLog(@"%@",[jsonDic objectForKey:@"userInfo" ]);  
    NSLog(@"%@",[dicUserInfo objectForKey:@"userName"]);  
    NSLog(@"%@",[dicUserInfo objectForKey:@"sex"]);  
}  

5、 处理json对象有多个记录的方法

[cpp]  view plain copy

        NSString * customerGridJsonString = [[NSString alloc]initWithString:@"{\"customer\":[{\"name\":\"roamer\",\"ycount\":\"232.4\",\"sumcount\":\"322.3\"},{\"name\":\"王三\",\"ycount\":\"221.2\",\"sumcount\":\"1123.2\"},{\"name\":\"李四\",\"ycount\":\"1221.2\",\"sumcount\":\"12123.2\"}]}"];  
          
        SBJsonParser * parser = [[SBJsonParser alloc] init];  
//        NSLog(@"%@",customerGridJsonString);  
        NSError * error = nil;  
          
        NSMutableDictionary *root = [[NSMutableDictionary alloc] initWithDictionary:[parser objectWithString:customerGridJsonString error:&error]];  
        NSLog(@"%@",root);  
        //注意转换代码  
        SBJsonWriter *jsonWriter = [[SBJsonWriter alloc] init];  
          
        NSString *jsonString = [jsonWriter stringWithObject:root];  
          
        [jsonWriter release];  
        NSLog(@"%@",jsonString);  
        //注意转换代码  
        NSMutableArray * customers = [root objectForKey:@"customer"];  
        NSLog(@"%@",customers);  http://www.huiyi8.com/moban/​
        for(NSMutableDictionary * member  in customers)  
        {  
            NSLog(@"%@",[[member objectForKey:@"name"] description]);  
        }  

6、递归遍历解析出的NSDictionary对象

[cpp]  view plain copy

-(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]];    
     }    
   }    
}    
7、将解析出的NSDictionary对象还原为json字符串 
[cpp]  view plain copy网站模板

NSString * jsonStr=[items JSONRepresentation];