Question

I’m learning C# by writing a home library manager.

I have a BookController that will store the books in a data structure and perform operations on them.

Does C# have a way of saving the data in the dictionary to a local file perhaps in an XML fashion to load later, or am I going to have to write it myself?

What is the best method of saving and loading this data available to C#? Just need pointed in a good direction.

Answer 1

Actually, C# (the language) doesn’t know anything about serialization, but .NET (the framework) provides lots of ways… XmlSerializer, BinaryFormatter, DataContractSerializer (.NET 3.0) – or there are a few bespoke serialization frameworks too.

Which to use depends on your requirements; BinaryFormatter is simple to use, but burns assembly metadata information into the file – making it non-portable (you couldn’t open it in Java, for example). XmlSerializer and DataContractSerializer are primarily xml-based, making it quite portable, but fairly large unless you compress it.

Some proprietary serializers are half-way between the two; protobuf-net is a binary formatter (so very dense data), but which follows a portable standard for the data format (Google’s protocol buffers spec). Whether this is useful depends on your scenario.

Typical code (here using XmlSerializer):

        XmlSerializer ser = new XmlSerializer(typeof(Foo));         // write         using (var stream = File.Create('foo.xml'))         {             ser.Serialize(stream, foo); // your instance         }         // read         using (var stream = File.OpenRead('foo.xml'))         {             Foo newFoo = (Foo)ser.Deserialize(stream);         }