Deserializing List with XmlSerializer Causing Extra Items

Question

I\'m noticing an odd behavior with the XmlSerializer and generic lists (specifically List). I was wondering if anyone has seen this before or knows w

Answer 1

It happens because you are initializing the List in the constructor. When you go to deserialize, a new ListTest is created and then it populate the object from state.

Think of the workflow like this

1. Create a new ListTest
2. Execute the Constructor (add 1,2,3,4)
3. Deserialize the xml state, and add 1,2,3,4 to the List

A simple solution would be to init the object outside the scope of the constructor.

public class ListTest
{
    public int[] Array { get; set; }
    public List<int> List { get; set; }

    public ListTest()
    {

    }

    public void Init() 
    {
        Array = new[] { 1, 2, 3, 4 };
        List = new List<int>(Array);
    }
}

ListTest listTest = new ListTest();
listTest.Init(); //manually call this to do the initial seed

Answer 2

The issue is that you're defining the original 1,2,3,4 in the List in the default constructor. Your deserializer is adding to the list, not defining it.