无法从填充了JSON数据的NSDictionary中提取数据

Question

我刚刚开始为IOS5编写应用程序。我目前有一个PHP Web服务，应用程序调用它来从数据库中检索数据。在数据库中，我现在有3行，当我进入调试器时，字典有3个键/值对。不过，我无法检索到任何值。下面的我的代码：

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，这是字典中包含的数据，我从调试器中得到了这些数据：

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;
    }
)

我希望有人能帮忙——我相信问题一定是基本的。

非常感谢，

Stephen

Answer 1

好的，这里得到的是字典数组，而不是字典本身。试试这个：

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

当然，这只会给你第一个物体，但你明白了。。。