Custom exceptions in c#.net

Custom exceptions in c#.net

Define custom exception class:
[Serializable]
public class CustomException : Exception
{
    public CustomException()  : base() { } 

    public CustomException(string message)  : base(message) { }  

    public CustomException(string format, params object[] args)  :
        base(string.Format(format, args)) {  }  

    public CustomException(string message, Exception innerException) :
                                                         base(message, innerException) {  }

    public CustomException(string format, Exception innerException, params object[] args)  :
                                                         base(string.Format(format, args), innerException) { }  

    protected CustomException(SerializationInfo info, StreamingContext context) :
           base(info, context) { }

}

Example:
1. Throw exception with out message:
         throw new CustomException()
2. Throw exception with simple message:
       throw new CustomException(message)
3. Throw exception with message format and parameters:
      throw new CustomException("Exception with parameter value '{0}'", param)
4. Throw exception with simple message and inner exception:
      throw new CustomException(message, innerException)
5. Throw exception with message format and inner exception. Note that, the variable length params
    are always floating:
     throw new CustomException("Exception with parameter value '{0}'", innerException, param)
6. The last flavor of custom exception constructor is used during exception   
    serialization/deserialization.