LinkedList<T> can not be serialized using the XMLSerializer
A LinkedList can't be serialized using XmlSerializer.
Now, how to however save/retrieve data from a serialized objet LinkedList. Should I implement custom serialization?
What I tried to do:
using System.Xml.Serialization;
[Serializable()]
public class TestClass
{
private int _Id;
private string _Name;
private int _Age;
private LinkedList<int> _linkedList = new LinkedList<int>();
public string Name {
get { return _Name; }
set { _Name = value; }
}
public string Age {
get { return _Age; }
set { _Age = value; }
}
[XmlArray()]
public List<int> MyLinkedList {
get { return new List<int>(_linkedList); }
set { _linkedList = new LinkedList<int>(value); }
}
}
What I've obtained(addind name, age and some items in the mylinkedlist):
<开发者_开发知识库;?xml version="1.0"?>
<TestClass
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Name>testName</Name>
<Age>10</Age>
<MyLinkedList />
</TestClass>
So, the items in the linked list hadn't been serialized... :(
One possibility would be the creation of a serializable collection that contains the same objects as the linked list. E.g. (untested):
LinkedList<Foo> ll = PopulateLinkedList();
List<Foo> list = new List<Foo>(ll);
Then serialize list
instead. This isn't going to create a lot of overhead if Foo
is a reference type, and you don't care about the fact that insertions/deletions are now more expensive b/c you're only using the List<T>
to hold references to the data for serialization and deserialization purposes. When you pull it out of the serialized stream, you can just turn it back into a LinkedList<T>
to get all those advantages you were using a linked list for in the first place.
Here's a little console app I just whipped up to demonstrate. I did it in VS2008, but I don't think I used anything surprising-- just the array initialization syntax to save some vertical space.
Sample Code:
[Serializable]
public class MyClass
{
private string name;
private int age;
private LinkedList<int> linkedList = new LinkedList<int>();
public string Name
{
get { return name; }
set { name = value; }
}
public int Age
{
get { return age; }
set { age = value; }
}
[XmlArray]
public List<int> MyLinkedList
{
get { return new List<int>(linkedList); }
set { linkedList = new LinkedList<int>(value); }
}
}
And the main application code:
class Program
{
static void Main(string[] args)
{
MyClass c = new MyClass();
c.Age = 42;
c.Name = "MyName";
c.MyLinkedList = new List<int>() { 1, 4, 9 }; // Your property impl requires this be set all at once, not one element at a time via the property.
XmlSerializer s = new XmlSerializer(typeof(MyClass));
StringWriter outStream = new StringWriter();
s.Serialize(outStream, c);
Console.Write(outStream.ToString());
return;
}
}
This kicks the following out to the console:
<?xml version="1.0" encoding="utf-16"?>
<MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Name>MyName</Name>
<Age>42</Age>
<MyLinkedList>
<int>1</int>
<int>4</int>
<int>9</int>
</MyLinkedList>
</MyClass>
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