Order list by parent and child items
Given "Parent" is nullable property (assuming nullable int here). Following should give you parent-child related ordered list:
public class ProductDTO
{
public int Id { get; set; }
public string Name { get; set; }
public int? Parent { get; set; }
}
var products = new List<ProductDTO>();
products.Add(new ProductDTO() { Id = 1, Name = "Product One" });
products.Add(new ProductDTO() { Id = 2, Name = "Product Two" });
products.Add(new ProductDTO() { Id = 3, Name = "Product Three" });
products.Add(new ProductDTO() { Id = 4, Name = "Child One", Parent=1 });
products.Add(new ProductDTO() { Id = 5, Name = "Child Two", Parent = 2 });
products.Add(new ProductDTO() { Id = 6, Name = "Child One", Parent = 1 });
var ordered = products
.Where(p => p.Parent == null)
.OrderBy(p=> p.Id)
.Select(p => products
.Where(c => c.Parent == p.Id)
.OrderBy(c => c.Id))
.ToList();
you could try something like that. Assuming parent is a nullable:
var sorted = list.OrderBy(x => x.parent ?? x.id).ThenBy(x=>x.id);
if its a string:
var sorted = list.OrderBy(x =>
{
if (x.parent == "null")
return x.id;
else
return Convert.ToInt32(x.parent);
}).ThenBy(x => x.id);