四种方法解析JSON数据

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

 1 //使用TouchJson来解析北京的天气
 2 - (IBAction)btnPressTouchJson:(id)sender {
 3     //获取API接口
 4     NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101010100.html"];
 5     //定义一个NSError对象,用于捕获错误信息
 6     NSError *error;
 7     NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
 8     NSLog(@"jsonString--->%@",jsonString);
 9     //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
10     NSDictionary *rootDic = [[CJSONDeserializer deserializer] deserialize:[jsonString dataUsingEncoding:NSUTF8StringEncoding] error:&error];
11     //因为返回的Json文件有两层,去第二层内容放到字典中去
12     NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];
13     NSLog(@"weatherInfo--->%@",weatherInfo);
14     //取值打印
15     txtView.text = [NSString stringWithFormat:@"今天是 %@  %@  %@  的天气状况是:%@  %@ ",[weatherInfo objectForKey:@"date_y"]
16                   ,[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"],[weatherInfo objectForKey:@"weather1"]
17                   ,[weatherInfo objectForKey:@"temp1"]];
18 }

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

 1 //使用SBJson解析南阳的天气
 2 - (IBAction)btnPressSBJson:(id)sender {
 3     NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101180701.html"];
 4     NSError *error = nil;
 5     NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
 6     SBJsonParser *parser = [[SBJsonParser alloc] init];
 7     
 8     NSDictionary *rootDic = [parser objectWithString:jsonString error:&error];
 9     NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];
10     txtView.text = [NSString stringWithFormat:@"今天是 %@  %@  %@  的天气状况是:%@  %@ ",[weatherInfo objectForKey:@"date_y"]
11                   ,[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"],[weatherInfo objectForKey:@"weather1"]
12                   ,[weatherInfo objectForKey:@"temp1"]];
13 }

(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)

 1 - (IBAction)btnPressIOS5Json:(id)sender {
 2     
 3     NSError *error;
 4     //加载一个NSURL对象
 5     NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.weather.com.cn/data/101180601.html"]];
 6     //将请求的url数据放到NSData对象中
 7     NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
 8     //IOS5自带解析类NSJSONSerialization从response中解析出数据放到字典中
 9     NSDictionary *weatherDic = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];
10     NSDictionary *weatherInfo = [weatherDic objectForKey:@"weatherinfo"];
11     txtView.text = [NSString stringWithFormat:@"今天是 %@  %@  %@  的天气状况是:%@  %@ ",[weatherInfo objectForKey:@"date_y"]
12                   ,[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"],[weatherInfo objectForKey:@"weather1"]
13                   ,[weatherInfo objectForKey:@"temp1"]];
14     NSLog(@"weatherInfo字典里面的内容为--》%@", weatherDic );
15 }

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

 1 - (void)btnPressJsonKit:(id)sender {
 2     //如果json是“单层”的,即value都是字符串、数字,可以使用    objectFromJSONString  
 3 NSString *json1 = @"{"a":123, "b":"abc"}";
 4 NSLog(@"json1:%@",json1);
 5 NSDictionary *data1 = [json1 objectFromJSONString];
 6 NSLog(@"json1.a:%@",[data1 objectForKey:@"a"]);
 7 NSLog(@"json1.b:%@",[data1 objectForKey:@"b"]);  
 8 [json1 release]; 
 9 //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  
10 //(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:
11 NSString *json2 = @"{"a":123, "b":"abc", "c":[456, "hello"], "d":{"name":"张三", "age":"32"}}"; 
12 NSLog(@"json2:%@", json2);
13 NSDictionary *data2 = [json2 objectFromJSONStringWithParseOptions:JKParseOptionLooseUnicode];
14 NSLog(@"json2.c:%@", [data2 objectForKey:@"c"]); 
15 NSLog(@"json2.d:%@", [data2 objectForKey:@"d"]);
16 [json2 release];
17 }
原文地址:https://www.cnblogs.com/starainDou/p/5143404.html