Question

I’ve got a custom collection which adds functionality to the ‘ArrayList’ class.

Here’s some code from the class:

    [Serializable]
    class Coll : ArrayList
    {

       public void Save(string path)
            {
                BinaryFormatter formatter = new BinaryFormatter();
                FileStream fsOut = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
                formatter.Serialize(fsOut, this);
                fsOut.Dispose();
            }
    }

I’m now trying to deserialize a file, and fill the collection with the contents of the file. Basically the opposite of my Save(string path) method.

This is what I’ve got so far:

public void Read(string path)
            {
                BinaryFormatter formatter = new BinaryFormatter();
                FileStream fsIn = new FileStream(path, FileMode.Open, FileAccess.Read);
                formatter.Deserialize(fsIn);
                fsIn.Dispose();
            }

How should I go about populating the collection with the contents which has been deserialized?

Answer 1

BinaryFormatter doesn’t support serialising into an existing object. You could deserialize it into a new list – just make it a static method and return the value.

Other thoughts:

• don’t use ArrayList unless you are in .net 1.1: List<T> would be preferable
• no need to subclass; an extension method would suffice
• I don’t recommend BinaryFormatter for this… Or anything else really