Multiple Order By with LINQ [duplicate]
I start with a basic class that I want to manipulate in a List using LINQ, something like the following:
public class FooBar
{
public virtual int Id { get; set; }
public virtual string Foo { get; set; }
public virtual string Bar { get; set; }
}
This is what I ultimately found out to solve my problem using the non lambda LINQ stuff.
// code somewhere else that works and gets the desired results
var foobarList = GetFooBarList(); // Abstracted out - returns List<Foobar>
// Interesting piece of code that I want to examine
var resultSet = from foobars in foobarList
orderby foobars.Foo, foobars.Bar
select foobars;
// Iterate and do something interesting
foreach (var foobar in resultSet)
{
// Do some code
}
What I'm really curious about is if the same can be accomplished using the Lambda based extension methods off of generic IEnumerable
to accomplish the same thing. Google tells me I can do something like the following to accomplish it:
var resultSet = foobarList.OrderBy(x => new {x.Foo, x.Bar})
.Select(x=>x);
However if I do that I get a runtime error when I hit the foreach
statement. The error tells me that at least one object has to implement IComparible
, which I can see that since I'm using an anonymous type for the .OrderBy()
method.
So is there a way to accomplish what I want using the Lambda way?
Solution 1:
You can use the ThenBy and ThenByDescending extension methods:
foobarList.OrderBy(x => x.Foo).ThenBy( x => x.Bar)