Copy list object into object of another list object

mukesh kv

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

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes15y ago
Accepted 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.
Vulpes15y ago
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 kv15y ago
Hi Zoran, Can you please tell me how achieve it using AddRange? Thanks, Mukesh KV
mukesh kv15y ago
Thanks Vulpes :)
Zoran Horvat15y ago
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