ios学习笔记：jison（转）

NSJSONSerialization提供了Json数据封包、Json数据解析，NSJSONSerialization将JSON数据转换为NSDictionary或NSArray解包方法，将NSDictionary、NSArray对象转换为JSON数据（可以通过调用isValidJSONObject来判断NSDictionary、NSArray对象是否可以转换为JSON数 据）封包。这一篇将做简单介绍。

Json数据封包

 NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:@"value1",@"key1",@"value2",@"key2",@"value3",@"key3", nil];
    // isValidJSONObject判断对象是否可以构建成json对象
    if ([NSJSONSerialization isValidJSONObject:dic]){
        NSError *error;
        // 创造一个json从Data, NSJSONWritingPrettyPrinted指定的JSON数据产的空白，使输出更具可读性。
        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:&error];
        NSString *json =[[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
        NSLog(@"json data:%@",json);
    }

 

Json数据解析

 

NSError *error;
    //加载一个NSURL对象
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.weather.com.cn/data/101120101.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 *text = [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(@"weatherInfo：%@", text );