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。

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

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1. //测试json的解析  
2. -(void)testJsonParser: (NSString *) jsonString  
3. {  
4.     jsonString = [[NSString alloc] initWithString:@"{\"userInfo\":{\"userName\":\"张三\",\"sex\":\"男\"}}"];  
5.     NSLog(@"正在解析json字符串是：%@",jsonString);  
6.       
7.     SBJsonParser * parser = [[SBJsonParser alloc] init];  
8.     NSError * error = nil;  
9.     NSMutableDictionary *jsonDic = [parser objectWithString:jsonString error:&error];  
10.     NSMutableDictionary * dicUserInfo = [jsonDic objectForKey:@"userInfo"];  
11.       
12.     NSLog(@"%@",[jsonDic objectForKey:@"userInfo" ]);  
13.     NSLog(@"%@",[dicUserInfo objectForKey:@"userName"]);  
14.     NSLog(@"%@",[dicUserInfo objectForKey:@"sex"]);  
15. }  

5、 处理json对象有多个记录的方法

[cpp]  view plain copy

1.         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\"}]}"];  
2.           
3.         SBJsonParser * parser = [[SBJsonParser alloc] init];  
4. //        NSLog(@"%@",customerGridJsonString);  
5.         NSError * error = nil;  
6.           
7.         NSMutableDictionary *root = [[NSMutableDictionary alloc] initWithDictionary:[parser objectWithString:customerGridJsonString error:&error]];  
8.         NSLog(@"%@",root);  
9.         //注意转换代码  
10.         SBJsonWriter *jsonWriter = [[SBJsonWriter alloc] init];  
11.           
12.         NSString *jsonString = [jsonWriter stringWithObject:root];  
13.           
14.         [jsonWriter release];  
15.         NSLog(@"%@",jsonString);  
16.         //注意转换代码  
17.         NSMutableArray * customers = [root objectForKey:@"customer"];  
18.         NSLog(@"%@",customers);  
19.         for(NSMutableDictionary * member  in customers)  
20.         {  
21.             NSLog(@"%@",[[member objectForKey:@"name"] description]);  
22.         }  

6、递归遍历解析出的NSDictionary对象

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1. -(void)visitDict:(NSDictionary *)dict{    
2.   NSArray *keys=[dict allKeys];    
3.   for (NSString *key in keys) {    
4.      NSString *result=[NSString stringWithFormat:@"key=%@,value=%@",key,[dict objectForKey:key]];    
5.      NSLog(result);    
6.      if([[dict objectForKey:key] isKindOfClass:[NSDictionary class]]){    
7.             [self visitDict:[dict objectForKey:key]];    
8.      }    
9.    }    
10. }    

7、将解析出的NSDictionary对象还原为json字符串

[cpp]  view plain copy

1. NSString * jsonStr=[items JSONRepresentation];