BinaryFormatter and Deserialization Complex objects

Question

Can not deserialize following object graph. That Exception occurs when deserialize method called on BinaryFormmater: System.Runtime.Serialization.SerializationException :

The constructor to deserialize an object of type 'C' was not found. 

There're two constructor on C. and I think the problem may be : While serialization Binaryformatter using the paramatered one and on deserialization process, it needs a parameterless one. Is there a hack / solution? Objects :

  [Serializable]     public class A     {         B b;         C c;          public int ID { get; set; }          public A()         {         }          public A(B b)         {             this.b = b;         }          public A(C c)         {             this.c = c;         }     }     [Serializable]     public class B     {      }     [Serializable]     public class C : Dictionary<int, A>     {         public C()         {          }          public C(List<A> list)         {             list.ForEach(p => this.Add(p.ID, p));         }     } 

// Serialization success

    byte[] result;     using (var stream =new MemoryStream())     {         new BinaryFormatter ().Serialize (stream, source);         stream.Flush ();         result = stream.ToArray ();     }     return result; 

// Deserialization fails

    object result = null;     using (var stream = new MemoryStream(buffer))     {         result = new BinaryFormatter ().Deserialize (stream);     }     return result; 

The calls are at the same environment, same thread, same method

        List<A> alist = new List<A>()         {             new A {ID = 1},             new A {ID = 2}         };          C c = new C(alist);         var fetched = Serialize (c); // success         var obj = Deserialize(fetched); // failes 

Answer 1

I suspect you just need to provide a deserialization constructor to C, since dictionary implements ISerializable:

protected C(SerializationInfo info, StreamingContext ctx) : base(info, ctx) {} 

checked (passes):

 static void Main() {      C c = new C();      c.Add(123, new A { ID = 456});      using(var ms = new MemoryStream()) {          var ser = new BinaryFormatter();          ser.Serialize(ms, c);          ms.Position = 0;          C clone = (C)ser.Deserialize(ms);          Console.WriteLine(clone.Count); // writes 1          Console.WriteLine(clone[123].ID); // writes 456      }  }