[摘要]本文是對ios 中使用SBJson拼接和解析json的講解，對學習IOS蘋果軟件開發有所幫助,與大家分享。

1.ios解析json
使用開源json包，項目地址：
http://stig.github.com/json-framework/
NSData * responseData = [respones responseData];

NSString * strResponser = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
SBJsonParser * parser = [[SBJsonParser alloc]init];
NSMutableDictionary *dicMessageInfo = [parser objectWithString:strResponser]; // 解析成json解析對象
[parser release];
//發送者
NSString * sender = [dicMessageInfo objectForKey:@"sender"];

2.json嵌套對象解析：
//要上傳的字符串
NSString *dataStr=[[NSString alloc] initWithString:@"{\"cross\":{\"1\":\"true\",\"2\":\"false\",\"3\":\"true\"}}"];
//獲取響應返回字符串
NSData * responseData = [respones responseData];

NSString * strResponser = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
//嵌套解析
SBJsonParser * parser = [[SBJsonParser alloc]init];

NSMutableDictionary *dicMessageInfo = [parser objectWithString:strResponser]; // 解析成json解析對象

NSMutableDictionary * cross = [dicMessageInfo objectForKey:@"cross"];

NSString *cross1= [cross objectForKey:@"1"];
//解析json到各個字符串
//發送者
[parser release];
NSLog(@"cross1: %@",cross1);
3.拼接json字符串

通過使用SBJson中的SBJsonWriter類的方法- (NSString*)stringWithObject:(id)value可以將一個對象中的值格式化為json字符串，符合key/value格式的數據封裝到NSDictionary後可以使用該方法進行格式化，其他數據通過拼接字符串的方式格式化。
在拼接過程中可以使用類NSMutableString的方法：
- (void)appendString:(NSString *)aString;、
- (void)appendFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1,2);
動態添加字符串。
拼接的字符串可通過json在線驗證的方式驗證其格式是否正確，網址為：
http://jsonlint.com/
-(NSString *) getJsonString
{
NSMutableString *json = [NSMutableString stringWithCapacity:128];
NSString *jsonString=nil;
SBJsonWriter *writer = [[SBJsonWriter alloc] init];
[json appendString:@"{\"data\":{"];
[json appendFormat:@"\"%@\":\"%d\",",@"reset",reset];
if(missionStatus!=NULL)
{
jsonString=[writer stringWithObject:status];
if(jsonString!=NULL)
{
[json appendString:@"\"status\":"];
[json appendString:jsonString];
}
}
[json appendString:@"}}"];
return json;
}
4.利用多個NSDictionary，拼接多層嵌套的json字符串，減少因手工拼接忘記加引號導致的json格式錯誤
示例代碼：
NSDictionary *dataDictionary= [NSDictionary dictionaryWithObjectsAndKeys:mac,@"mac",
game,@"game",
devicetoken,@"devicetoken",
device,@"device",
gv,@"gv",
lang,@"lang",
os,@"os",
hardware,@"hardware",
down,@"down",nil];
NSDictionary *parmDictionary= [NSDictionary dictionaryWithObjectsAndKeys:@"getSession",@"act",
dataDictionary,@"data",nil];
NSDictionary *jsonDictionary=[NSDictionary dictionaryWithObjectsAndKeys:pv,@"pv",
parmDictionary,@"param",nil];
SBJsonWriter *writer = [[SBJsonWriter alloc] init];

NSString *jsonString=nil;
jsonString=[writer stringWithObject:jsonDictionary];
NSLog(@"%@",jsonString);
5.json字符串在線校驗網址：
http://jsonlint.com/