Skip to main content

Serialization and Exceptions !!!

I am just in a stage like Alice in Wonderland, and not yet got out of the wonders of the .NET framework, C# and the VS 2003(5) IDE. I thought that the serialization is all not my thing until I do something big in C#. I had written this custom exception class in my project that has 3 processes connected by .NET Remoting Infrastructure. I throw my custom exception for a scenario but all I got was some other exception that said "The constructor to deserialize an object of type MyException was not found". But I had the Serializable attribute tagged to my custom expection class.

Let me to get to the point. Even though you attach the Serializable attribute to your custom exception class, the base class Exception implements the ISerializable interface and the constructor required during the deserialization [Exception()] is protected. So when you throw MyException, it may get serialized and cross the remoting boundaries but on the client side, it will not able to deserialize because the required ctor is not accessible. So what we do is simple as shown in the following code:-
[Serializable]
public class MyException : ApplicationException
{
// Member Data

// Other necessary ctors

///
/// Let us call this ctor as Deserializing Ctor [DSCTOR]
///

public MyException(SerializationInfo info,
StreamingContext context)
: base(info, context)
{
// Any other custom data to be transferred
// info.AddValue(CustomDataName, DataValue);
}

///
/// If any custom information needs to be transferred
/// with the MyException thown, it must be added to the
/// SerializationInfo object on the call to
/// GetObjectData() and to take them from this object in
/// the constructor for deserialization.
///

public override void GetObjectData(SerializationInfo info,
StreamingContext context)
{
base.GetObjectData(info, context);
// Any other custom data to be transferred
// info.AddValue(CustomDataName, DataValue);
}

// Other methods
}
This DSCTOR is very much necessary, else the exception thrown will not be caught as the one thrown and you will get this excepetion "The constructor to deserialize an object of type MyException was not found".

If any custom data needs to be transferred with the MyException thown, it must be added to the SerializationInfo object on the call to GetObjectData() and to take them from this object in this secondary [deserialization] constructor.

Comments

Popular posts from this blog

Extension Methods - A Polished C++ Feature !!!

Extension Method is an excellent feature in C# 3.0. It is a mechanism by which new methods can be exposed from an existing type (interface or class) without directly adding the method to the type. Why do we need extension methods anyway ? Ok, that is the big story of lamba and LINQ. But from a conceptual standpoint, the extension methods establish a mechanism to extend the public interface of a type. The compiler is smart enough to make the method a part of the public interface of the type. Yeah, that is what it does, and the intellisense is very cool in making us believe that. It is cleaner and easier (for the library developers and for us programmers even) to add extra functionality (methods) not provided in the type. That is the intent. And we know that was exercised extravagantly in LINQ. The IEnumerable was extended with a whole lot set of methods to aid the LINQ design. Remember the Where, Select etc methods on IEnumerable. An example code snippet is worth a thousand ...

Wetting my feet in Android - Seinfeld Calendar

A couple of my colleagues and I huddled up to learn a bit of Android. I think I told you about that a short while back. We developed a very simple application - The Seinfeld Calendar . Seinfeld calendar, or otherwise called the habit calendar, is Seinfeld's productivity secret . The secret of achieving your goal is practising something, whatever your goal is, everyday and make it a habit. And mark it in your calendar each day you practice, and make sure you do not break the chain. Our application helps you keep track of your everyday tasks. Our application does not jog or meditate or quit smoking for you. You have to do your tasks. Our application provides the facility to create tasks for the habits you wish to pursue, which in certain cases like smoking means quitting. And then you mark each day in the calendar if you pursued your task, else you don't mark and break the chain. And no cheating! The application is in very nascent stage and does not provide you (fancy) s...

Implementing COM OutOfProc Servers in C# .NET !!!

Had to implement our COM OOP Server project in .NET, and I found this solution from the internet after a great deal of search, but unfortunately the whole idea was ruled out, and we wrapped it as a .NET assembly. This is worth knowing. Step 1: Implement IClassFactory in a class in .NET. Use the following definition for IClassFactory. namespace COM { static class Guids { public const string IClassFactory = "00000001-0000-0000-C000-000000000046"; public const string IUnknown = "00000000-0000-0000-C000-000000000046"; } /// /// IClassFactory declaration /// [ComImport(), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid(COM.Guids.IClassFactory)] internal interface IClassFactory { [PreserveSig] int CreateInstance(IntPtr pUnkOuter, ref Guid riid, out IntPtr ppvObject); [PreserveSig] int LockServer(bool fLock); } } Step 2: [DllImport("ole32.dll")] private static extern int CoR...