iOS中四种解析Json的方法

本文将介绍TouchJson、 SBJson 、JSONKit 和 iOS5所支持的原生的json方法，解析国家气象局API，TouchJson和SBJson需要下载他们的库

TouchJson包下载： http://download.youkuaiyun.com/detail/enuola/4523169

SBJson 包下载： http://download.youkuaiyun.com/detail/enuola/4523177

JSONKit包下载：http://download.youkuaiyun.com/detail/enuola/4523160

下面的完整程序源码包下载：http://download.youkuaiyun.com/detail/enuola/4523223

（1）使用TouchJSon解析方法：（需导入包：#import “TouchJson/JSON/CJSONDeserializer.h”）

Objective-C

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//使用TouchJson来解析北京的天气   - (void)btnPressTouchJson:(id)sender {       //获取API接口       NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101010100.html"];       //定义一个NSError对象，用于捕获错误信息       NSError *error;       NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];       NSLog(@"jsonString--->%@",jsonString);       //将解析得到的内容存放字典中，编码格式为UTF8，防止取值的时候发生乱码       NSDictionary *rootDic = [[CJSONDeserializer deserializer] deserialize:[jsonString dataUsingEncoding:NSUTF8StringEncoding] error:&error];       //因为返回的Json文件有两层，去第二层内容放到字典中去       NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];       NSLog(@"weatherInfo--->%@",weatherInfo);       //取值打印       NSString *detail = [NSString stringWithFormat:@"今天是 %@  %@  %@  的天气状况是：%@  %@ ",[weatherInfo objectForKey:@"date_y"]                         ,[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"],[weatherInfo objectForKey:@"weather1"]                         ,[weatherInfo objectForKey:@"temp1"]];       NSLog(@"%@",detail);   }

（2）使用 SBJson解析方法：（需导入包：#import “SBJson/SBJson.h”）

Java

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//使用SBJson解析南阳的天气   - (void)btnPressSBJson:(id)sender {       NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101180701.html"];       NSError *error = nil;       NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];       SBJsonParser *parser = [[SBJsonParser alloc] init];              NSDictionary *rootDic = [parser objectWithString:jsonString error:&error];       NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];   NSString *detail = [NSString stringWithFormat:@"今天是 %@  %@  %@  的天气状况是：%@  %@ ",[weatherInfo objectForKey:@"date_y"]                         ,[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"],[weatherInfo objectForKey:@"weather1"]                         ,[weatherInfo objectForKey:@"temp1"]];     NSLog(@"%@",detail); }

（3）使用 IOS5自带解析类NSJSONSerialization方法解析：（无需导入包，IOS5支持，低版本IOS不支持）

Java

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- (void)btnPressIOS5Json:(id)sender {              NSError *error;       //加载一个NSURL对象       NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.weather.com.cn/data/101180601.html"]];       //将请求的url数据放到NSData对象中       NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];       //IOS5自带解析类NSJSONSerialization从response中解析出数据放到字典中       NSDictionary *weatherDic = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];       NSDictionary *weatherInfo = [weatherDic objectForKey:@"weatherinfo"];       NSString *detail = [NSString stringWithFormat:@"今天是 %@  %@  %@  的天气状况是：%@  %@ ",[weatherInfo objectForKey:@"date_y"]                         ,[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"],[weatherInfo objectForKey:@"weather1"]                         ,[weatherInfo objectForKey:@"temp1"]];     NSLog(@"%@",detail);   NSLog(@"weatherInfo字典里面的内容为--》%@", weatherDic );   }

（4）使用 JSONKit的解析方法：（需导入包：#import “JSONKit/JSONKit.h”） 

Objective-C

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- (void)btnPressJsonKit:(id)sender {              //如果json是“单层”的，即value都是字符串、数字，可以使用objectFromJSONString       NSString *json1 = @"{\"a\":123, \"b\":\"abc\"}";       NSLog(@"json1:%@",json1);       NSDictionary *data1 = [json1 objectFromJSONString];       NSLog(@"json1.a:%@",[data1 objectForKey:@"a"]);       NSLog(@"json1.b:%@",[data1 objectForKey:@"b"]);       [json1 release];              //如果json有嵌套，即value里有array、object，如果再使用objectFromJSONString，程序可能会报错       //（测试结果表明：使用由网络或得到的php/json_encode生成的json时会报错，但使用NSString定义的json字符串时，解析成功），最好使用objectFromJSONStringWithParseOptions：       NSString *json2 = @"{\"a\":123, \"b\":\"abc\", \"c\":[456, \"hello\"], \"d\":{\"name\":\"张三\", \"age\":\"32\"}}";       NSLog(@"json2:%@", json2);       NSDictionary *data2 = [json2 objectFromJSONStringWithParseOptions:JKParseOptionLooseUnicode];       NSLog(@"json2.c:%@", [data2 objectForKey:@"c"]);       NSLog(@"json2.d:%@", [data2 objectForKey:@"d"]);       [json2 release];   }