Copy list object into object of another list object

Question

Hi all I have two list objects say List and List class PDTO { public string Prop1{get; set;} } class UPDTO { public PDTO oPDTO {get; set;} } I have data in List . And I want this to get copied to the object (PDTO) that I have in List . Could you please let me know the solution? We can do the same like the below: foreach (PDTO oPDTO1 in oListPDTO) { oListUPDTO.Add(new UPDTO() { oPDTO = oPDTO1 }); } Is there any better way of doing this? Thanks Mukesh KV

Vulpes · Answer

There isn't really a better way to do it because there's no escaping the fact that you have to create a new UPDTO object for each PDTO in oListPDTO. An alterative way to do it would be to use LINQ: oListUPDTO = (from oPDTO1 in oListPDTO select new UPDTO() { oPDTO = oPDTO1 }).ToList(); but frankly I'd leave it as you have it.

Vulpes · Answer

The only way I can get Zoran's suggestion to work is like this: using System; using System.Collections.Generic; using System.Linq; public class PDTO { public string Prop1{get; set;} public static implicit operator UPDTO(PDTO pdto) { return new UPDTO(){ oPDTO = pdto }; } } public class UPDTO { public PDTO oPDTO {get; set;} } static class Program { static void Main() { List oListPDTO = new List (); oListPDTO.Add(new PDTO(){Prop1 = Mukesh}); oListPDTO.Add(new PDTO(){Prop1 = Vulpes}); oListPDTO.Add(new PDTO(){Prop1 = Zoran}); List oListUPDTO = new List (); oListUPDTO.AddRange(oListPDTO.Select(pdto => (UPDTO)pdto)); foreach(UPDTO updto in oListUPDTO) Console.WriteLine(updto.oPDTO.Prop1); Console.ReadKey(); } } Genetic interface covariance doesn't seem to work with custom conversions nor does the Cast operator. However using Select to do the conversions works fine and an explicit rather than an implicit conversion then suffices. So it's still quite a neat approach.

mukesh kv · Answer

Hi Zoran Can you please tell me how achieve it using AddRange? Thanks Mukesh KV

mukesh kv · Answer

Thanks Vulpes :)

Zoran Horvat · Answer

Maybe you can define implicit conversion from PDTO to UPDTO if construction of UPDTO is so simple. In that case I believe that simple List.AddRange would work correctly i.e. call conversion method for every member of the class. Zoran