Why catch and rethrow an exception in C#?

Question

I\'m looking at the article C# - Data Transfer Object on serializable DTOs.

The article includes this piece of code:

public static string Se         


        

Answer 1

A valid reason for rethrowing exceptions can be that you want to add information to the exception, or perhaps wrap the original exception in one of your own making:

public static string SerializeDTO(DTO dto) {
  try {
      XmlSerializer xmlSer = new XmlSerializer(dto.GetType());
      StringWriter sWriter = new StringWriter();
      xmlSer.Serialize(sWriter, dto);
      return sWriter.ToString();
  }
  catch(Exception ex) {
    string message = 
      String.Format("Something went wrong serializing DTO {0}", DTO);
    throw new MyLibraryException(message, ex);
  }
}