无法从填充了JSON数据的NSDictionary中提取数据 [英] Cannot extract data from NSDictionary filled with JSON Data

问题描述

我刚刚开始为IOS5编写应用程序。我目前有一个PHP Web服务，应用程序调用该服务从数据库中检索数据。在数据库中，我目前有3行，当我进入调试器时，字典有3个键/值对。我无法检索任何值。我的代码如下：

I have just started writing apps for IOS5. I currently have a PHP webservice that the app calls to retrieve data from database. In the database I have 3 rows at the moment, and when I go into the debugger the dictionary has 3 key/value pairs. I cannot retrieve any of the values though. My Code below:

NSURL *myUrl = [[NSURL alloc]initWithString:@"http://localhost/~stephen-hill9/index.php"];
NSData *data = [[NSData alloc] initWithContentsOfURL:myUrl];
NSError *error;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
NSLog(@"Parsed Data: %@", json);
NSDictionary *bodyDictionary = [json objectForKey:@"Product_Desc"]; <-APP CRASHES HERE - INVALID KEY
NSLog(@"Parsed Data: %@", bodyDictionary);

此外，这是我从调试器获得的字典所包含的数据：

Also, here is the data that the dictionary contains which I got from the debugger:

Parsed Data: (
        {
        0 = 1;
        1 = "Caromax 20HN B/F";
        2 = 51533;
        3 = 6650;
        4 = 1117760;
        5 = 1067224;
        6 = 1759741;
        7 = 1;
        8 = "0000-00-00 00:00:00";
        ID = 1;
        "Max_Volume" = 1759741;
        "Product_Code" = 51533;
        "Product_Desc" = "Caromax 20HN B/F";
        Pumpable = 1067224;
        Status = 1;
        "Tank_Level" = 6650;
        Updated = "0000-00-00 00:00:00";
        Volume = 1117760;
    },
        {
        0 = 2;
        1 = "C1 Kerosine";
        2 = 25101;
        3 = 1258;
        4 = 146871;
        5 = 111776;
        6 = 1018590;
        7 = 2;
        8 = "2023-02-12 20:00:00";
        ID = 2;
        "Max_Volume" = 1018590;
        "Product_Code" = 25101;
        "Product_Desc" = "C1 Kerosine";
        Pumpable = 111776;
        Status = 2;
        "Tank_Level" = 1258;
        Updated = "2023-02-12 20:00:00";
        Volume = 146871;
    },
        {
        0 = 3;
        1 = "Recovered Spirit";
        2 = 87902;
        3 = 6069;
        4 = 710172;
        5 = 675078;
        6 = 1018200;
        7 = 1;
        8 = "2012-03-16 00:00:00";
        ID = 3;
        "Max_Volume" = 1018200;
        "Product_Code" = 87902;
        "Product_Desc" = "Recovered Spirit";
        Pumpable = 675078;
        Status = 1;
        "Tank_Level" = 6069;
        Updated = "2012-03-16 00:00:00";
        Volume = 710172;
    }
)

我希望有人能够提供帮助 - 我肯定问题必须是基本的。

I hope someone is able to help - I am sure the problem must be something basic.

非常感谢提前，

Stephen

推荐答案

好的，你在这里得到的是一个字典数组，而不是字典本身。
试试这个：

Ok, what you 've got here is an Array of Dictionaries, not a Dictionary itself. Try this:

NSArray *json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
NSDictionary *bodyDictionary = [json objectAtIndex:0];

当然这只会让你成为第一个对象，但你明白了......

Of course this will get you the first object only, but you get the idea...

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