Viv,

This probably doesn't apply, but it rang a bell with me, so I thought I'd share. Peter Bromberg showed some custom binary serialization at an MVP-to-MVP session at the MVP Summit this past week. Although, I think what he showed in his session was a bit simpler than what's in this article, so maybe this isn't it. But, anyway, if it helps give you ideas, great ... if not, oh well! <g>

http://www.eggheadcafe.com/tutorials/aspnet/03c16f90-6745-44c6-8d83-f768d09949de/silverlight-2-beta-2-doi.aspx


~~Bonnie


>Hi,
>
>I posted this in the WPF category and got no replies - but it's not really a WPF specific thing so I'm trying again here:
>
>I think I'm missing something simple. Here's a simple class:

>public class ShapeCanvas4 : Canvas
>{
>    public string SomeField;
>    public ShapeCanvas4()
>    {
>    }
>}

And here's an equally simple Serialization surrogate:

public class ShapeCanvas4Surrogate : ISerializationSurrogate
>  {
>   public void GetObjectData(object obj, SerializationInfo info, StreamingContext context)
>   {
>        ShapeCanvas4 sc3 = (ShapeCanvas4)obj;
>        info.AddValue("SomeField", sc3.SomeField);
>        info.AddValue("Name", sc3.Name);
>   }
>    public object SetObjectData(object obj, SerializationInfo info, StreamingContext context, ISurrogateSelector selector)
>    {
>        ShapeCanvas4 sc4 = (ShapeCanvas4)obj;
>        sc4.SomeField =info.GetString("SomeField");
>        string s = info.GetString("Name");
>        sc4.Name = s;
>        return sc4;
>    }
>}

I instantiate an instance of ShapeCanvas4, set SomeField to something, register the surrogate with a BinaryFormatter and serialize it. When I deserialize I get an InvalidOperationException on the line "sc4.Name = s;" Message is "Current local value enumeration is outdated because one or more local values have been set since its creation.". Anyone know why this doesn't work ?
>
>Update: For completeness here's the test code:

>ShapeCanvas4 sc4 = new ShapeCanvas4();
>sc4.SomeField = "Fred";
>
>MemoryStream fs = new MemoryStream();
>BinaryFormatter formatter = new BinaryFormatter();
>
>SurrogateSelector ss = new SurrogateSelector();
>ShapeCanvas4Surrogate sc4Surrogate = new ShapeCanvas4Surrogate();
>ss.AddSurrogate(typeof(ShapeCanvas4), new StreamingContext(StreamingContextStates.All), sc4Surrogate);
>formatter.SurrogateSelector = ss;
>
>formatter.Serialize(fs, sc4);
>fs.Position = 0;
>ShapeCanvas4 newSC4 = (ShapeCanvas4)formatter.Deserialize(fs);

>(Guess I should have posted this in a general .NET category since it's not WPF specific)