complex List<> sorting

[Tem]

I have an Interface InterfaceBase, and two classes Type 1 and Type 2 that
implements InterfaceBase

Class Type1 has a string property Title
Class Type2 has a string property Title and an int property Ordering

List<BaseC> list

I would like to sort the list by the value of Ordering (Type 1's Ordering is
always 0) and a secondary order by the string property Title alphabetically.

I tried writing my own Comparision code, it doesn't seem to work

Thanks for your help

Tem

 

[Tem]

I would like to know how to write this in LINQ

 

[Gilles Kohl [MVP]]

I have an Interface InterfaceBase, and two classes Type 1 and Type 2 that
implements InterfaceBase

Class Type1 has a string property Title
Class Type2 has a string property Title and an int property Ordering

I assume neither property is part of the interface?

List<BaseC> list

What is BaseC as opposed to InterfaceBase?

I would like to sort the list by the value of Ordering (Type 1's Ordering is
always 0) and a secondary order by the string property Title alphabetically.

I tried writing my own Comparision code, it doesn't seem to work

Could you post some actual code - or maybe a simplified, but
compileable version of what you are trying to do - it is hard to help
without knowing the details or seeing what you tried that didn't work.

Regards,
Gilles.

 

[Tem]

Sorry it's a typo it's supposed to be List<InterfaceBase> list

 

[Tem]

I've decided to use another method to store the data.

Thank you guys for your help.

 

[Marc Gravell]

I would like to know how to write this in LINQ

You don't need LINQ for this; you can sort the existing list using a
Comparer<T>:

List<InterfaceBase> list = new List<InterfaceBase>();

list.Sort((x, y) =>
{
int result = x.Ordering.CompareTo(y.Ordering);
if (result == 0) result = string.Compare(x.Title, y.Title);
return result;
});

or in C# 2 (VS2005):

list.Sort(delegate (InterfaceBase x, InterfaceBase y)
{
int result = x.Ordering.CompareTo(y.Ordering);
if (result == 0) result = string.Compare(x.Title, y.Title);
return result;
});

If you really want to use LINQ, you can - but note that you get a new
list - you don't sort the existing one:

List<InterfaceBase> newList = (
from item in list
orderby item.Ordering, item.Title
select item).ToList();

Marc