In this topic: /backoffice-extensions/nupickers/questionssuggestions/60250-How-does-relations-work

This works:

 var relations = ApplicationContext.Services.RelationService.GetByParentId(CurrentPage.Id).

but this does not

var relations = ApplicationContext.Services.RelationService.GetByParentId(CurrentPage.Id).Where(r => r.RelationTypeId = 2);

or maybe the slightly nicer:

var relations = ApplicationContext.Services.RelationService.GetByParentId(CurrentPage.Id).Where(r => r.RelationType.Alias = "x2y");

Cannot use a lambda expression as an argument to a dynamically dispatched operation without first casting it to a delegate or expression tree type

I have no idea at all what this means and google isn't really helping me. It just seems to be telling me that what I am trying to do is "bad" as apparently it couldn't be unit tested. I don't really understand, and would appreciate some guidance.

This is the whole error message:

Compiler Error Message: CS1977: Cannot use a lambda expression as an argument to a dynamically dispatched operation without first casting it to a delegate or expression tree type
Source Error:

Line 3:  @{
Line 4:      Layout = null;
Line 5:      var relations = ApplicationContext.Services.RelationService.GetByParentId(CurrentPage.Id).Where(r => r.RelationTypeId = 2);

Source File: c:\inetpub\v7test\Views\x.cshtml    Line: 5