IOS开发学习27 ObjectC 自带json解析方法的使用

NSMutableDictionary * header=[NSMutableDictionary dictionaryWithObjectsAndKeys:@"2015-02-03 19:15:00",@"timestamp",nil];

NSError *error=nil;
NSData *jsonData=[NSJSONSerialization dataWithJSONObject:header options:kNilOptions error:&error];
NSString *json =[[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];

NSData* data=[msg dataUsingEncoding:NSUTF8StringEncoding];
NSError *error=nil;
id json=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&error];
if([json isKindOfClass:[NSDictionary class]]){
NSDictionary *dictionary=(NSDictionary*)json;
//取值
if([dictionary valueForKey:@"code"]){
NSNumber *code=dictionary[@"code"];
}
//赋值
[dictionary setValue:@"value" forKey:@"key"];
}