This seems to be simple, but I'm not sure what I'm doing wrong...
I wrote the following Class, which I further use it in a Dictionary<string, ClassName>
object, as its .Value
:
public class StorageList
{
static List<int> listForStorage = new();
public void AddToListForStorage(int number)
{
listForStorage.Add(number);
}
public List<int> GetList()
{
return listForStorage;
}
}
When I run the application, I create a Dictionary<string, StorageList>
and add a few elements to it:
static void Main(string[] args)
{
Dictionary<string, StorageList> dictionary = new();
dictionary.Add("idOne", new StorageList());
dictionary.Add("idTwo", new StorageList());
dictionary["idOne"].AddToListForStorage(1);
dictionary["idOne"].AddToListForStorage(2);
dictionary["idTwo"].AddToListForStorage(3);
dictionary["idTwo"].AddToListForStorage(4);
}
When printing to the console either 'idOne' or 'idTwo', I was expecting to see 1 and 2 for 'idOne' and 3 and 4 for 'idTwo. However, I see 1, 2, 3 and 4 for both 'idOne' and 'idTwo'...
foreach (var id in dictionary)
{
foreach (var item in dictionary[id.Key].GetList())
{
Console.WriteLine(item);
}
Console.WriteLine($"Finished {id.Key}");
}
// 1
// 2
// 3 <-- Not expected
// 4 <-- Not expected
// Finished idOne
// 1 <-- Not expected
// 2 <-- Not expected
// 3
// 4
// Finished idTwo
Objects are different, so I don't quite understand why this is happening.
Console.WriteLine(Object.ReferenceEquals(dictionary["idOne"], dictionary["idTwo"]));
// false
I'd appreciate some assistance on this. Thanks!
You have declared listForStorage
as static
, so it belongs to the StorageList
type rather than any specific instance of StorageList
.
Consequentially, there will be only one List<int>
instance used by all instances of StorageList
.
That being said, you probably want to make listForStorage
an instance variable (remove the static
keyword):
public class StorageList
{
List<int> listForStorage = new();
}
Now each instance of StorageList
will have its own listForStorage
.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.