NSJSONSerialization 是解析json的自带的ios 类，使用它可以解析json 的信息。除了读取xml外，json也是比较常用的一些数据操作。之前用了一下，现在记录一下。

下面记录一下json的页面信息，以获取天气的信息json来解析一下。

{"weatherinfo":{"city":"北京","cityid":"101010100","temp":"9","WD":"西南风","WS":"2级","SD":"22%","WSE":"2","time":"10:45","isRadar":"1","Radar":"JC_RADAR_AZ9010_JB","njd":"暂无实况","qy":"1014"}}

使用NSData 直接来读取远程的数据

NSString *jsonPath  =@"http://www.weather.com.cn/adat/sk/101010100.html";
 NSData *jsonData = [NSData dataWithContentsOfURL:[NSURL URLWithString:jsonPath]];    
 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&error];
 NSDictionary *weatherDic =  [dic objectForKey:@"weatherinfo"];
 NSLog(@"JSON 城市 %@",[weatherDic objectForKey:@"city"]);
 NSLog(@"JSON 城市ID %@",[weatherDic objectForKey:@"cityid"]);
 NSLog(@"JSON 温度 %@",[weatherDic objectForKey:@"temp"]);

使用NSURLConnection 读取json的信息

NSURLRequest *resuest  = [NSURLRequest requestWithURL:[NSURL URLWithString:jsonPath]];

 [NSURLConnection sendAsynchronousRequest:resuest queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response,NSData *data,NSError *connectionError){       
      NSError *error = nil;
      NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
      NSDictionary *weatherDic =  [dic objectForKey:@"weatherinfo"];
      NSLog(@"JSON 城市 %@",[weatherDic objectForKey:@"city"]);
      NSLog(@"JSON 城市ID %@",[weatherDic objectForKey:@"cityid"]);
      NSLog(@"JSON 温度 %@",[weatherDic objectForKey:@"temp"]);    
    }];

NSData 也是使用频繁的一个类，经常会涉及到。