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c#linqlinq-to-objectsanonymous-types
Martin
Martin

Reputation: 24308

LINQ: Calling a Method from within linq?, my method returns an anonymous type

Can anyone help. I have the following as part of a LINQ, its working but the object MyObject returns an anonymous type. (I checked it in debug mode)

  {System.Linq.Enumerable.WhereSelectEnumerableIterator<<>f__AnonymousType1<MyType.ParamRow,MyType.Row>,object>}

Here is part of my query

select new Param
{
   Name ="Test1",
   MyObject = (from o1 in otherObject.Object join o2 in otherObject.ObjectB on
                 o1.Id equals o2.Id
                   where o.Id == o2.Id select this.BuildMyObject("DataObject", o1))
}

I think i am using the select wrong....

Basically MyObject returns type of object but this 

    select this.BuildMyObject("DataObject", o1)

returns an anonymous type. I want to create a real type of Object..

I think I am doing something wrong.

EDIT

Build my object is very simple currently I am returning a TextBox (textbox is a class of mine) as you can see it returns OBJECT

    private object BuildMyObject(string type, TestStructure.ParamRow item)
    {

        MyTextBox control = new MyTextBox();

        control.Name = "NotEmpty";
        return control

    }

Upvotes: 3

Views: 234

Answers (2)

Marc Gravell
Marc Gravell

Reputation: 1062510

Looking at your MyObject, I believe all you are seeing here is the concrete type that is underpinning an IEnumerable<object>. This is because you aren't limiting to a single object. If you expect one row, tell it:

select new Param
{
   Name ="Test1",
   MyObject = (from o1 in otherObject.Object
               join o2 in otherObject.ObjectB on o1.Id equals o2.Id
               where o.Id == o2.Id select this.BuildMyObject("DataObject", o1)
              ).First()
}

Otherwise, just access MyObject as an IEnumerable<object>, and you should find that each row is actually a MyTextBox; i.e.

var sequence = (IEnumerable<object>) param.MyObject;
foreach(MyTextBox tb in sequence) {
    // should work
}

but note that this is different to it being an IEnumerable<MyTetxBox>; for that, you would use .Cast<MyTextBox>()

Upvotes: 1

Marc Gravell
Marc Gravell

Reputation: 1062510

That is how the compiler implements joins; it creates an anonymous type representing the various forms. You should be able to fix this in a select, for example:

select Tuple.Create(o1, o2);

or if you only need o1:

select o1;

Upvotes: 1

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