[英]C# issue storing objects into Dictionaries
This seems to be simple, but I'm not sure what I'm doing wrong...这似乎很简单,但我不确定我做错了什么......
I wrote the following Class, which I further use it in a Dictionary<string, ClassName>
object, as its .Value
:我写了以下 Class,我在
Dictionary<string, ClassName>
object 中进一步使用它作为它的.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:当我运行应用程序时,我创建了一个
Dictionary<string, StorageList>
并向其中添加了一些元素:
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.当打印到控制台“idOne”或“idTwo”时,我希望看到“idOne”的 1 和 2,以及“idTwo”的 3 和 4。 However, I see 1, 2, 3 and 4 for both 'idOne' and 'idTwo'...
但是,我看到 'idOne' 和 'idTwo' 的 1、2、3 和 4...
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.对象不同,所以我不太明白为什么会这样。
Console.WriteLine(Object.ReferenceEquals(dictionary["idOne"], dictionary["idTwo"]));
// false
I'd appreciate some assistance on this.我很感激这方面的一些帮助。 Thanks!
谢谢!
You have declared listForStorage
as static
, so it belongs to the StorageList
type rather than any specific instance of StorageList
.您已将
listForStorage
声明为static
,因此它属于StorageList
类型,而不是StorageList
的任何特定实例。
Consequentially, there will be only one List<int>
instance used by all instances of StorageList
.因此,所有
StorageList
实例将只使用一个List<int>
实例。
That being said, you probably want to make listForStorage
an instance variable (remove the static
keyword):话虽如此,您可能希望将
listForStorage
实例变量(删除static
关键字):
public class StorageList
{
List<int> listForStorage = new();
}
Now each instance of StorageList
will have its own listForStorage
.现在
StorageList
的每个实例都有自己的listForStorage
。
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