How to OrderBy ASC or DESC a specific column in LINQ according to parameters

Question

I am generating a result using the following LINQ query:

var field = "FirstName"; // or "LastName"
var type = "asc"; // or "desc"

var result = (from x in db.ContactSet
              select new
              {
                  x.FirstName,
                  x.LastName
              }).ToList();

I need to orderby asc or desc (based off the type variable) for the field variable.

How can I do this in a clean way?

EDIT: The question referred to by the duplicate does not answer this.

Possible duplicate of [Dynamic LINQ OrderBy on IEnumerable](http://stackoverflow.com/questions/41244/dynamic-linq-orderby-on-ienumerablet) — ASh, Mar 31 '17 at 12:48
If you know the fieldnames on compile time, why would you specify the sorting column name as dynamic? — Jeroen van Langen, Mar 31 '17 at 13:11
I only know them at runtime, I just put that there for simplicity of the question. — Barry Michael Doyle, Mar 31 '17 at 13:13
By the way, second answer in duplicate question is exactly the same as the answer you accepted. — Evk, Mar 31 '17 at 18:08

score 3 · Accepted Answer · answered Mar 31 '17 at 12:53

3

Use Dynamic Linq

Then you can write something like this...

var field = "FirstName"; // or "LastName"
var type = "ascending"; // or "descending" <-- full 

var result = (from x in db.ContactSet
          select new
          {
              x.FirstName,
              x.LastName
          }).ToList();

result = result.OrderBy(field + " " + type).ToList();

answered Mar 31 '17 at 12:53

Marko Juvančič

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The type arguments for method (IEnumerable, Func)' cannot be inferred from the usage. Try specifying the type argument explicitly. – Barry Michael Doyle Mar 31 '17 at 12:57
1

@BarryMichaelDoyle The answer requires [Dynamic Linq](https://dynamiclinq.codeplex.com/) _(like he explained)_ – Jeroen van Langen Mar 31 '17 at 13:10
I had to head out quickly so I can only check this out when I get back again in two hours. Didn't realize I needed a package. Thanks for clarifying. – Barry Michael Doyle Mar 31 '17 at 13:44

How to OrderBy ASC or DESC a specific column in LINQ according to parameters

1 Answers1