Dictionary containing with only Serializable objects

Question

I am looking for a way to ensure that only serializable objects are stored into a Dictionary in C#.

To be more specific I'm looking to do something similar to this:

Dictionary<String, ISerializable> serialDict = new Dictionary<String, ISerializable>();

The problem with this is that I cannot store primitive types like integers, booleans, or strings.

Is there a way to ensure that my Dictionary contains only objects which can be serialized?

Answer 1

I don't think you can do this at compile-time, but you can do it at runtime. If you build your own class deriving from Dictionary<TKey, TValue>, then in the constructor of your class, you can check the attributes attached to the TValue type, and make sure SerializableAttribute is one of them, else throw an exception.

All of the standard primitive types (int, bool, etc.) have this attribute.

Answer 2

One thing to consider is that in classes that are serializable are tagged with the SerializableAttribute as opposed to implementing an interface. From MSDN:

Any class that might be serialized must be marked with the SerializableAttribute. If a class needs to control its serialization process, it can implement the ISerializable interface.

What you would need to do is make your own class that implements the IDictioanry interface and every time someone calls add, use reflection to check if the element passed in has a serializable attribute (and throw an exception if it doesn't).

Code would look something like

class MyDictionary<TKey, TValue> : IDictionary<TKey, TValue> 
{
    private Dictionary<TKey, TValue> d;

    public void Add(TKey key, TValue value)
    {
        if( value.GetType().IsSerializable )
        {
            d.Add(key, value);
        }
        else 
        {
            throw new ArgumentException();
        }
    }
    .....
}