Serialize ArrayList of Objects

Question

I have an ArrayList which stores a custom object. I want to serialize that ArrayList to a string so I can save it inside the Application settings.

This question looks to resolve it, but is in java. And I am not smart with XML, so could someone help out? Serialize an ArrayList of Date object type

I have my ArrayList setup:

...
MyObject tempObj = new MyObject("something",1,"something");
MyCollection.Add(tempObj);
...

And I originally had this. It outputs the string, but the object isn't there:

    private string SerializeArrayList(ArrayList obj)
    {
            System.Xml.XmlDocument doc = new XmlDocument();
            Type[] extraTypes = new Type[1];
            extraTypes[0] = typeof(MyObject);
            System.Xml.Serialization.XmlSerializer serializer = new System.Xml.Serialization.XmlSerializer(typeof(ArrayList), extraTypes);
            System.IO.MemoryStream stream = new System.IO.MemoryStream();
            try
            {
                serializer.Serialize(stream, obj);
                stream.Position = 0;
                doc.Load(stream);
                return doc.InnerXml;
            }
            catch { throw; }
            finally
            {
                stream.Close();
                stream.Dispose();
            }
}

EDIT: Code request

    public class MyObject
    {
        private string eN;      
        private Boolean bE;          
        private int min;         
        private Boolean bot;       
        private string onE;         


        public MyObject(string na, Boolean b)
        {
          ...
        }


        public MyObject()
        {
        }

        public string GetSomething()
        {
            ...

Could you add the code for `MyObject`? Also, could you add the result you are getting and the result you are expecting? — svick, Feb 03 '13 at 18:08
What do you mean by "It outputs the string, but the object isn't there"? You are trying to serialize to string right? — Geethanga, Feb 03 '13 at 18:12
Yes I am calling it like string tmp = SerializeArrayList(MyCollection); will edit main. — JEV, Feb 03 '13 at 19:32
Have you marked your custom object's class as `serializable`? — DeanOC, Feb 03 '13 at 19:44
If your ArrayList always contains items of the same kind, then why not use `List`>? `ArrayList` is obsolete. — John Saunders, Feb 03 '13 at 20:56
I was unaware ArrayList was obsolete. I have been using the List<> on Java. How do I mark my class as Serilizable? — JEV, Feb 03 '13 at 20:58
ArrayList has been obsolete since .NET 2.0. Use `List` instead. — John Saunders, Feb 03 '13 at 23:38

score 5 · Accepted Answer · answered Feb 03 '13 at 22:43

I tested your code and it seems to work ok, as long as you have [Serializable] on your object.

Also if you are trying to Serialize the fields, you will have to make them public properties.

My Test:

    ArrayList array = new ArrayList();
    Rules tempObj = new Rules { onE = "Value", min = 45, eN = "Value" };
    array.Add(tempObj);
    string result = SerializeArrayList(array);

    private string SerializeArrayList(ArrayList obj)
    {
        XmlDocument doc = new XmlDocument();
        XmlSerializer serializer = new XmlSerializer(typeof(ArrayList), new Type[]{typeof(Rules)});
        using (MemoryStream stream = new System.IO.MemoryStream())
        {
            try
            {
                serializer.Serialize(stream, obj);
                stream.Position = 0;
                doc.Load(stream);
                return doc.InnerXml;
            }
            catch (Exception ex)
            {
            }
        }
        return string.Empty;
    }

Object:

[Serializable]
[XmlType(TypeName = "Rules")]
public class Rules
{
    // Make fields propertys so they will be serialized
    public string eN { get; set; }      //Name
    public Boolean bE { get; set; }     //Whether blocked entirely
    public int min { get; set; }        //Minutes they are allowed if blocked
    public Boolean bot { get; set; }    //Create notification if allowance exceed
    public string onE { get; set; }     //Nothing or CLOSE Process

    public Rules(string na, Boolean b)
    {

    }

    public Rules()
    {
    }
}

I did not have that [Serializable] at the top, so will look inot that. Thanks — JEV, Feb 04 '13 at 10:33
You are todays winner! Didn't know about having to have the get/setters instead of initializing in constructor. Thanks dude — JEV, Feb 04 '13 at 11:19
!!MUST declare getters/setters in order for serialization to work! — Steinfeld, May 15 '14 at 09:28

score 3 · Answer 2 · answered Feb 03 '13 at 20:54

3

I ran into a similar problem, and there is this great program called SharpSerializer, which is available through Nuget. It will handle your ArrayList quite easily, just type the code:

 SharpSerializer mySerializer = new SharpSerializer();
 mySerializer.Serialize(ArrayList, "filetosaveto.xml");

Here's the link to the website, its free so don't worry about paying anything:

http://www.sharpserializer.com/en/index.html

answered Feb 03 '13 at 20:54

David Venegoni

508
3
13

I appreciate the answer, however I am looking for a manual solution instead. Given you an upvote though :) – JEV Feb 03 '13 at 20:59
I understand. I am hopeful someone who is good with XML will give you some feedback on your problem. If not, you could look into the source code for SharpSerializer and see if that helps you at all. Either way, hope you figure it out. – David Venegoni Feb 03 '13 at 21:43

Serialize ArrayList of Objects

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