Unable to find assembly exception,when perform deserialization

Question

My winforms application has a custom control, one of its property "LayoutStream" is byte[] type and it is serializable property. Currently I have ported my application from 4.6 framework to NetCore 3.0 project.

While run ported NetCore 3.0 project, im getting below exception when deserialize the data from resx file.

this.control1.LayoutStream = ((SerializableByteList)(resources.GetObject("control1.LayoutStream")));


    public SerializableByteList LayoutStream
    {
        get
        {
            return LayoutStream;
        }
        set
        {
            LayoutStream= value;
            if (value != null)
                this.stmLayout.Write(value.Bytes.ToArray(), 0, value.Bytes.ToArray().Length);
        }
    }

    [Serializable]
    public class SerializableByteList 
    {
        public SerializableByteList()
        {
            Bytes = new List<byte>();
        }
        public List<byte> Bytes { get; set; }
    }

Exception Occurs: Exception thrown: 'System.Runtime.Serialization.SerializationException' in System.Runtime.Serialization.Formatters.dll An unhandled exception of type 'System.Runtime.Serialization.SerializationException' occurred in System.Runtime.Serialization.Formatters.dll Unable to find assembly 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'

Please suggest solution to resolve this.

Marc Gravell Marc Gravell · Accepted Answer · 2019-10-15T10:03:04

Fundamentally, BinaryFormatter is not portable; it was designed for remoting between two nodes running identical code, not persisting data between frameworks. So: my main advice is simply:

Don't use BinaryFormatter. Ever.

I realise this boat may have sailed, but a very pragmatic option is to:

pick a new serializer - making sure it is portable (json, xml, protobuf, etc); just about anything except BinaryFormatter
in your old code, deserialize the data with your current code, and serialize it separately with the new choice of serializer
in your new code, deserialize it in the new format only

At a push, however, you could try playing with a custom SerializationBinder; the idea here is that you subclass SerializationBinder, override the methods, and tell it where to find things. The fundamental problem here is that:

the assemblies (mscorlib etc) have changed identity
types have moved between assemblies in many cases

Both of those problems need handling.

Partial code:

var bf = new BinaryFormatter { Binder = MyBinder.Instance };
// etc

with

class MyBinder : SerializationBinder
{
    private MyBinder() { }
    public static MyBinder Instance { get; } = new MyBinder();
    public override Type BindToType(string assemblyName, string typeName)
    {
        // TODO: check assemblyName and typeName against some known list, and
        // return the Type that should be used, often *instead of* the
        // one it expected;
    }
    public override void BindToName(Type serializedType,
        out string assemblyName, out string typeName)
    {
        //TODO: the opposite
    }
}

But this is hard work, and absurdly brittle. Your time would be much better spent porting to a different serializer, IMO. Happy to recommend some, depending on your needs.

Side note: they have tried repeatedly to kill BinaryFormatter for .NET Core, but it sadly survived.

Unable to find assembly exception,when perform deserialization

1 Answers